Since joining the Boston organization in the middle of last month, Belisario has thrown 6 1/3 scoreless innings, allowing just four hits but permitting three walks to go with his two strikeouts. But the results have been there all year at the Triple-A level. Including his time in the Rays organization, Belisario has tossed 36 2/3 frames of 2.70 ERA baseball at the minors’ highest level.

Belisario was somewhat less productive in a brief stint with Tampa Bay earlier in the year, allowing seven earned runs in eight frames. More concerning, perhaps, is that he showed a marked decreased in velocity. After averaging better than 94 mph on his fastball for his career, Belisario showed a sub-92 mph offering with the Rays.

While he also struggled to keep runs off the board last year for the White Sox, and has not posted above-average run prevention numbers since 2012, Belisario continues to fare well in the eyes of ERA estimators. He carries a lifetime 3.26 SIERA and has never ended a MLB season with a mark of over 3.46 in that metric.

It stands to reason that another organization will give the veteran a shot, particularly with the trade market now complicated by the need to pass players through waivers.

Belisario signed a split contract with the Rays last winter and only appeared in six big league games with the team, posting a 7.88 ERA over eight relief innings.  Belisario then elected free agency after being outrighted off Tampa’s roster.  Given how Boston’s bullpen has struggled this year, there’s certainly opportunity for the 32-year-old to find regular work in the Sox relief corps.

Prior to the 2015 season, Belisario held a career 3.75 ERA, 7.3 K/9 and 2.17 K/BB rate over 331 1/3 innings with the Dodgers and White Sox.  He’s coming off a tough 5.56 ERA over 66 1/3 IP with Chicago in 2014, though advanced metrics indicate that Belisario was rather unlucky to post such an unsightly ERA.  Belisario is a ground-ball specialist (60.9% career grounder rate), which should help him at hitter-friendly Fenway Park.

• Righty Ben Rowen has opted out of his contract with the Orioles and is now a free agent, MASNsports.com’s Steve Melewski reports (via Twitter).  Rowen’s contract gave him the option of opting out if he wasn’t on the team’s MLB roster by July 1.  Rowen has a 2.41 ERA, 24 strikeouts and six walks over 37 1/3 Triple-A relief innings this season, and he appeared eight big league games with Texas in 2014.
• Earlier this week, the Twins signed veteran righty Scott Atchison to a minor league contract, according to MLB.com’s official transactions page.  Atchison his the open market last week when he was released by the Indians.  Atchison posted a 6.86 ERA, 5.5 K/9 and a 3:1 strikeout-to-walk ratio over 19 2/3 innings out of Cleveland’s bullpen this season, though with strong numbers in 2011-14, it’s a no-risk signing by the Twins to see if Atchison can regain his form.
• Reliever Ronald Belisario, who was recently outrighted by the Rays, has cleared waivers and elected to become a free agent, Marc Topkin of the Tampa Bay Times tweets. The Rays recently designated Belisario for assignment after he allowed seven runs in eight innings in a brief stint with the team covering two weeks in late June.
• The Mariners have outrighted outfielder Julio Morban, MLB.com’s Greg Johns tweets. The move clears a spot on the Mariners’ 40-man roster, which now stands at 39. Morban, 23, had a pair of strong seasons in 2012 at Class A+ High Desert and in 2013 at Double-A Jackson. He has struggled with injury throughout his career, however, and his performance has tailed off significantly in the past two seasons. He only recently returned from a two-month stay on the restricted list due to personal reasons.
• The Mariners have released righty Justin Germano and lefty Rafael Perez, Bob Dutton of the Tacoma News Tribune reports. Both of them had out clauses. Germano confirms (via Twitter) that he will head to Korea to pitch with the KT Wiz. The 32-year-old was in the midst of a good season for Triple-A Tacoma, with a 2.83 ERA, 6.6 K/9 and 1.4 BB/9 in 89 innings. The 33-year-old Perez had been on loan to Quintana Roo in the Mexican League and had not actually pitched in the Mariners system.
• The Rangers have traded outfielder Jake Skole to the Yankees for cash, FOX Sports Southwest’s Anthony Andro tweets. Skole, the 15th overall pick in the 2010 draft, was hitting .218/.313/.335 for Double-A Frisco, consistent with his walk-heavy but generally unimpressive offensive performances throughout the minor league career.
• Andy Oliver has opted out of his minor league deal with the Rays, Marc Topkin of the Tampa Bay Times tweets. The 27-year-old Oliver has good stuff, particularly for a lefty, but has struggled with control problems throughout his career. He had a 3.86 ERA and 10.3 K/9 but with 7.7 BB/9 in 28 innings for Triple-A Durham. The Phillies took him in the Rule 5 Draft last winter, but he elected free agency after they outrighted him in April.
• The Giants have signed outfielder Xavier Avery to a minor league deal, Andrew Baggarly of the Mercury News tweets. The 25-year-old Avery opted out of his deal with the Tigers this week after hitting .305/.371/.393 for Triple-A Toledo. The Giants have assigned him to Triple-A Sacramento.
• The Orioles have signed Cuban first baseman Yaisel Mederos, MASNsports.com’s Roch Kubatko tweets. The 25-year-old Mederos hit .268/.343/.402 in parts of four seasons in Cuba’s Serie Nacional. He only hit 12 home runs in 531 plate appearances, although Kubatko notes that Mederos has power potential.

Tampa Bay recently decided to add the 32-year-old to its big league roster when he exercised an opt-out clause in his minor league deal. Since that time, Belisario has thrown eight innings for the club — including his appearance tonight — and allowed seven earned runs. He has compiled six strikeouts against four walks on the year.

Belisario was throwing rather well in Triple-A, sporting a 3.26 ERA with 5.3 K/9 against 2.7 BB/9 over 30 1/3 frames. And he’s had success in the big leagues in the past. But clubs considering Belisario will surely note that his fastball velocity (in his few big league outings this year) was down about two miles per hour from recent seasons.

YESTERDAY: Rays pitcher Ronald Belisario has triggered his opt-out clause, Marc Topkin of the Tampa Bay Times reports (Twitter links). The provision affords the club until Wednesday to decide whether to promote the reliever, per the report.

As Topkin notes, the veteran righty has thrown well at Triple-A and seems a reasonable bet to receive a promotion. Acting as the closer at Triple-A Durham, Belisario has racked up 17 saves with a 3.26 ERA and 5.3 K/9 against 2.7 BB/9 in 30 1/3 innings.

Belisario struggled last year with the White Sox, but has had success at times in prior years with the Dodgers. All said, he has thrown 331 1/3 big league innings, posting a 3.75 lifetime ERA with 7.3 K/9 and 3.3 BB/9.

• When J.J. Hardy traded power to remain in the everyday lineup last season, he may have hurt his earning potential. Hardy is unsure if he would have re-signed with the Orioles had he not dealt with a painful back injury last season, writes Peter Schmuck of the Baltimore Sun. Baltimore inked Hardy to a three-year, $40MM extension during the playoffs last year. Hardy was aware of the trials suffered by Stephen Drew and former teammate Nelson Cruz in the previous offseason. Qualifying offers to both players left clubs wary about signing them. Hardy opted to forgo the experience entirely, although he also says he’s happy in Baltimore.
• Rays non-roster invitee Ronald Belisario injured himself climbing out of a pool earlier in the winter, writes Marc Topkin of the Tampa Bay Times. The reliever fractured his non-throwing shoulder prior to signing with the Rays a month ago. He didn’t have the injury checked out until he reported to camp. Belisario is on a split contract that would pay $1.5MM if he makes the team. Since he won’t be on the field for at least two weeks, his chances of breaking camp with the team look small. This injury probably explains why his deal with the Blue Jays fell through.

Here are a few more pitching notes from around the game:

• Ronald Belisario’s contract with the Rays can max out at $1.8MM if he reaches all of his incentives, tweets CBS Sports’ Jon Heyman. Belisario inked a minor league pact with the Rays over the weekend just days after a similar deal with the Blue Jays fell through. The right-hander will compete for a spot in Tampa’s bullpen this spring.
• The Twins are open to adding some relief help, according to previous reports, but Darren Wolfson of 1500 ESPN tweets that the team isn’t showing interest in righty David Aardsma at this time. The former Mariners closer, who enjoyed a strong season with the Cardinals’ Triple-A affiliate in 2014, will audition for clubs next Monday.
• Speaking of the Twins’ bullpen, MLB.com’s Rhett Bollinger did his best to sort out the many candidates in his latest Twins Inbox column. In addition to his take on who is most likely to comprise Minnesota’s relief corps in 2015, Bollinger notes that offseason signee Tim Stauffer will get a chance to earn a spot in the rotation, despite the fact that most believed he was signed as a bullpen addition.

The 32-year-old reliever was designated for assignment by the White Sox earlier in the offseason. He was one of several temporary closers for Chicago, although he struggled in the role. Before being cut loose by the White Sox, Belisario was in line to earn $3.9MM via arbitration, according to MLBTR’s Matt Swartz.

While he posted an unsightly 5.56 ERA last season, advanced stats painted a sunnier picture (3.54 FIP, 3.22 SIERA). The righty is a ground ball specialist with a career rate above 60 percent. Belisario dealt with a high .339 BABIP and low 57.5% strand rate last season, which contributed to his ugly ERA.

It’s possible that Tampa offered a better opportunity than Toronto for Belisario. As Topkin points out, the Rays have two open spots in the bullpen. Tropicana field is also substantially more pitcher friendly than the Rogers Centre.

JAN. 29: The Blue Jays added some depth to their bullpen mix today, agreeing to a minor league contract with right-hander Ronald Belisario. Toronto has long been said to be looking at bullpen upgrades, with reports last night suggesting that the team was looking hard at the free agent market. Though Belisario’s spot isn’t guaranteed, the McNamara Sports Group client will compete for a job in Spring Training and will reportedly earn $1.7MM if he makes the team.

Belisario, 32, was designated for assignment back in November by the White Sox to make way for the claim of Onelki Garcia. He was one of several players to slot in at closer last year in Chicago, but failed to grab hold of the job. Belisario was ultimately charged with an unsightly 5.56 ERA on the year.

Though the bottom-line results weren’t pretty, Belisario’s peripherals are decidedly better. With 6.4 K/9, 2.4 BB/9, and a stellar 59.3% groundball rate, Belisario drew marks from ERA estimators in the low-to-mid three range. His ballooned run tallies may well have been the result of a very low 57.7% strand rate and a somewhat bloated .339 BABIP.

Belisario had been projected by MLBTR/Matt Swartz to earn $3.9MM in arbitration before losing his roster spot in advance of the non-tender deadline. Toronto saw former closer Casey Janssen lured away with a total $5MM guarantee, though the club is said to have about that much in remaining payroll space.

Jon Morosi of FOX Sports reported, on Twitter, that the Jays were making a strong push for Belisario. ESPN’s Jim Bowden reported the agreement and terms (Twitter links).

Here are some more free agent notes:

• Fellow Cuban second bagger Hector Olivera will begin a two-day open showcase in the Dominican Republic tomorrow, Badler reports on Twitter. Olivera figures to be more of an immediate contributor than the younger Moncada.
• Clubs interested in righty Ronald Belisario, as with Burke Badenhop, include the Blue Jays and Nationals, per Jon Morosi of FOX Sports (via Twitter). The 32-year-old has run up solid innings totals over each of the last three years, but has seen his ERA steadily move north during that stretch. On the other hand, ERA estimators have viewed him as a solidly average performer in each of those seasons, with a low strand rate likely causing most of his troubles in 2014.
• The Yankees, Blue Jays, and Padres are three of the approximately six teams pursuing lefty Johan Santana, Jon Heyman of CBSSports.com tweets. An upcoming Venezuelan league start could have some bearing on where the one-time ace ends up.
• Another prominent lefty is plotting his comeback as well. Per Henry Schulman of the San Francisco Chronicle (Twitter link), Barry Zito still plans to return to baseball after a year off and will put on a showcase this spring. The 36-year-old last threw in 2013, working to a career-worst 5.74 ERA over 133 1/3 innings.

Some more notes from the free agent market…

• Also seeking a five-year deal is right-hander Ervin Santana, tweets ESPN’s Buster Olney. Santana is among the best of the bunch in the second tier of free agent starters, and he’s been rumored to have mutual interest with the Royals. However, Andy McCullough of the Kansas City Star tweets that the Royals’ comfort level is at three years with Santana. MLBTR’s Tim Dierkes projected a four-year, $56MM contract for Santana.
• Continuing on the theme of five-year contracts, Wallace Matthews of ESPN New York reports that the Yankees aren’t willing to give Chase Headley a five-year deal, and it’s believed by some that five years is now his asking price in the wake of both Pablo Sandoval and Hanley Ramirez signing in Boston. An alternative for the Yankees, Matthews writes, is to play Martin Prado at third base regularly and give prospect Rob Refsnyder a chance to be the everyday second baseman.
• The Yankees, Red Sox and Astros are all continuing to show strong interest in free agent lefty Andrew Miller, tweets Ken Rosenthal of FOX Sports. Miller is believed to be headed for a four-year deal, and the Astros have been somewhat surprisingly linked to him and fellow top reliever David Robertson.
• Geovany Soto is currently talking to five or six teams, tweets Chris Cotillo of SB Nation. A reunion between Soto and the Rangers is a definite possibility, per Cotillo. The free agent market for catchers has few options remaining, putting Soto in a relatively good spot.
• Anthony Fenech of the Detroit Free Press reports that 10 teams, including the Tigers, have reached out to free agent righty Ronald Belisario after he was designated for assignment by the White Sox and chose to elect free agency (Twitter link). Belisario has a track record of success but struggled in 2014 despite maintaining his velocity and ground-ball rate.
• Nyjer Morgan is eyeing a return to the Majors and has drawn interest from both MLB and Asian clubs, tweets Cotillo. The 34-year-old spent a bit of time with the Indians last season but had his Cleveland tenure cut short by injury.

Belisario, 32 on New Year’s Eve, pitched 66 1/3 innings for the White Sox in 2014, though he struggled to a 5.56 ERA with a below-average mark of 6.4 K/9. However, Belisario also posted a strong 2.4 BB/9 with an outstanding 59.3 percent ground-ball rate, leading metrics such as FIP (3.54) and SIERA (3.22) to feel that he was experienced some particularly poor luck. He did see his BABIP spike to a career-worst .339, and his 57.7 percent strand rate was well below both the league average and his career mark (69.9%).

Belisario has been a fixture in a big league bullpen in each of the past three seasons, averaging 68 innings per year with the White Sox and Dodgers. FIP and xFIP have graded him pretty consistently throughout his career and both feel he’s capable of an ERA in the 3.60 range, while SIERA (3.22) is a bit more bullish.

• Also outrighted today was Ramiro Pena of the Braves, per the MLB.com transactions page. The utility man was designated recently, presumably in large part due to his rising arbitration salary.
• Righty Blaine Boyer (Padres), Anthony Swarzak (Twins), and Juan Gutierrez (Giants) have elected free agency rather than accepting outright assignments, also via the MLB transactions page.
• The White Sox have outrighted righty Ronald Belisario, per the MLB.com transactions page. Belisario was designated recently to make room for the claim of reliever Onelki Garcia.
• Likewise, the Rays have outrighted righty Michael Kohn. It has been an odd start to the offseason for Kohn, who was signed to a MLB deal before being designated within weeks by Tampa.
• Baseball America’s Matt Eddy reported a number of new transactions in his weekly Minor League Transactions roundup on Monday. Of particular note is a crop of Phillies signings: catcher Koyie Hill, right-hander Paul Clemens, and infielders Chase d’Arnaud and Cord Phelps. Clemens gives them some pitching depth, as he’s totaled 98 innings with the Astros over the past two seasons, albeit with a 5.51 ERA.
• Also from Eddy, the Reds have inked outfielder Brennan Boesch to a minor league contract. The 29-year-old Boesch hit .269/.330/.436 in 248 games with the Tigers from 2010-11, but since that time, he’s batted just .237/.277/.376 in 635 plate appearances with the Tigers, Yankees and Angels.
• The Tigers have announced that outfielder Ezequiel Carrera has elected free agency rather than accepting an assignment to Triple-A after being outrighted (Twitter link). The 27-year-old hit .261/.301/.348 in 73 plate appearances with Detroit this season and is a lifetime .253/.305/.340 hitter in the Majors. Carrera hasn’t hit much in 478 big league PAs, but he brings some speed and solid baserunning to the table and is capable of handling all three outfield spots.

Garcia is an intriguing pick-up for Chicago. The 25-year-old has only limited big league experience, but has already racked up over a year of service time due to injury. But he has one solid season under his belt in the upper minors, back in 2012, and his live arm was intriguing enough that Baseball America rated him the Dodgers’ ninth-best prospect heading into 2014 in spite of his having undergone an elbow procedure. As BA wrote, the Cuban has a big fastball and good curve with plenty of upside if he can improve his control and add polish.

Belisario, 31, spent some time as Chicago’s closer in his first season with the Pale Hose, but he struggled overall. The former Dodger pitched to a 5.56 ERA with 6.4 K/9 and 2.4 BB/9 in 66 1/3 innings. However, Belisario’s FIP and SIERA feel that he was markedly better than his ERA. Indeed, much of those struggles seem to have come from a fluke 57.7 percent strand rate — significantly lower than his career mark of 70 percent. Belisario was also plagued by a .339 BABIP despite having posted a .288 mark for his career in that department. There were some positives to his game this past season, including an average fastball velocity of 93.9 mph and a strong 59.3 percent ground-ball rate. Nonetheless, Chicago apparently wasn’t comfortable with his projected arbitration salary of $3.9MM.

Mitchell, 26, was the Sox’ No. 1 pick back in 2009 (23rd overall) and ranked among the game’s Top 100 prospects according to both Baseball America and Baseball Prospectus that offseason. However, the LSU product has yet to show the offense one would hope for from a first-round outfielder, as he’s batted just .219/.341/.348 in parts of three seasons at the Triple-A level.

Belisario posted a 3.97 ERA with 6.5 K/9 and 3.7 BB/9 in 2013. In 265 career innings, he has a 3.29 ERA with 7.5 K/9 and 3.6 BB/9. He's known for his plus fastball, which averaged 94.4 MPH in 2013. The White Sox can now control Belisario's rights through 2016, since he can be eligible for arbitration again prior to the 2015 and 2016 seasons.