Brad Keller Elects Free Agency

Red Sox right-hander Brad Keller has elected to become a free agent, reports Alex Speier of the Boston Globe. As a player with five-plus years of big league service, Keller must consent to being optioned to the minors. He agreed to be optioned once earlier this season, but when the Red Sox sought to option him earlier this week, he instead exercised his right to become a free agent and seek a new opportunity.

Keller, 29, was a fixture in the Royals’ rotation from 2018-23. One of the more successful Rule 5 picks in recent memory — Kansas City plucked him out of the D-backs’ organization in the 2017 Rule 5 Draft — he enjoyed three sharp seasons as a starter for the Royals before struggling repeatedly from 2021-23, often due to injuries. After logging a 3.50 ERA in 360 1/3 innings for K.C. from 2018-20, Keller was roughed up for a 5.14 mark in the three subsequent seasons. Things went way off the rails in 2023, when he walked 45 hitters in 45 1/3 innings before going on the injured list and eventually undergoing thoracic outlet surgery.

The White Sox signed Keller to a minor league deal over the winter, and he had a brief run with Chicago before being designated for assignment and electing free agency. The Red Sox scooped him up in late May. After a tough debut in Baltimore, he settled in to pitch well over a string of eight long-relief appearances, but Boston sent him to the minors in late June (a move he approved at the time). He was recalled on Friday, surrendered three runs in four innings against the Astros on Saturday, and was optioned back to Triple-A Worcester on Monday — this time exercising his right to become a free agent.

Overall, Keller has pitched 37 1/3 innings between the ChiSox and BoSox this season. He’s logged a discouraging 5.30 ERA in that time, but his season isn’t without its silver linings. First and foremost, the disastrous command issues he displayed last season have come back down to Earth. In fact, Keller has not only put last year’s ghastly 21.3% walk rate behind him — he’s sporting a career-low 7.7% walk rate in his 37 1/3 frames. His 17.8% strikeout rate is below the league average but is right in line with the 17.4% mark he posted prior to his TOS-ruined 2023 season. Keller has seen the velocity on his four-seamer and sinker tick up slightly (though he’s also primarily been working in relief, so that’s not necessarily due to better health), and this year’s 9.1% swinging-strike rate is the second-best mark of his career (but still worse than league-average).

Down in Triple-A, things have gone better. He’s pitched a nearly identical slate of 38 innings there and has similar walk and strikeout rates to the ones he’s posted in the majors. However, he’s sporting a 4.26 ERA that’s more than a full run lower than his MLB ERA, due largely to the fact that he’s been able to avoid the long ball in a way he hasn’t at the MLB level (0.24 HR/9 in Triple-A, 1.93 HR/9 in MLB). In all likelihood, his home run rate in the majors is due for some positive regression, while his home run rate in the minors is likely due to swing the other direction.

For a team needing some late-season rotation depth or length in the bullpen, the veteran Keller could be a worthy flier. The Twins, Astros, Guardians, Mets, Braves and Padres are among the postseason hopefuls who have incurred injuries or are experiencing notable workload concerns among their current crop of starting pitchers.