Big Hype Prospects: Sheehan, Perez Jr., Kjerstad, Walker, Mervis

Our Arizona Fall League prospect coverage is coming to a close. The league wraps up its postseason this weekend. We’ll use this opportunity for one last peek at game action before affiliated baseball closes down for the year.

Five Big Hype Prospects

Emmet Sheehan, 22, SP, LAD (AA)
AFL: 20.1 IP, 8 BB, 24 K, 3.54 ERA

Arguably the top pitching prospect in the AFL, Sheehan had a shaky start to his fall season. He ended with a masterpiece: a five-inning, 10-strikeout gem. He allowed one hit and one walk in the outing. A right-handed changeup specialist, command is the main bugaboo when it comes to Sheehan’s development. His repertoire plays together in a way that should flummox hitters at all levels. As a Dodger, there is increased pressure to refine his command if he wants to stick in the rotation. Most clubs would comfortably view him as a future starter – one who might fumble a few games in the early innings but make up for it by dominating in others. The Dodgers could yet opt to turn him into a swing-man or reliever as they have with several able pitching prospects in recent years.

Robert Perez Jr., 22, 1B, SEA (A+)
AFL: 77 PA, 3 HR, .231/.338/.415

A slow-burn prospect whose calling card is power, Perez neither seized nor fumbled his opportunity in the AFL. The Rule 5-eligible first baseman has impressive power which he put on display by winning the first Fall Stars Home Run Derby. He performed well during the regular season – mostly at Low-A where he was a tad old for the level. His potent regular season and passable AFL campaign should lead to a promotion to Double-A early in the season. Whether or not the Mariners opt to add him to their 40-man, the right-handed slugger probably isn’t ready for a straight jump to the Majors via the Rule 5 Draft. Even in the AFL, he struck out 22 times in 77 plate appearances (28 percent).

Heston Kjerstad, 23, OF, BAL (A+)
AFL: 104 PA, 5 HR, .357/.385/.622

Few players had more to prove this fall than Kjerstad. Now that the smoke has cleared, he answered some questions and raised others. The left-handed hitting outfielder led the league in plate appearances and at bats. He recorded five walks and 31 strikeouts. Given the modest quality of pitching in the AFL, it’s fair to wonder about his combination of aggression and swing-and-miss tendencies. This is a long-standing issue dating back to pre-draft reports. He worked on it during the regular season – possibly to the detriment of his power. On-site observers raved about the quality of Kjerstad’s contact… whenever he connected. Between premium exit velocities, plenty of fly balls, and all those at bats, it’s no surprise he led the league in extra-base hits.
Such prospects succeed when they’re adept at making adjustments. Kjerstad should get his first taste of the upper minors at some point next season.

Jordan Walker, 20, OF/3B, STL (AA)
AFL: 90 PA, 5 HR, 3 SB, .286/.367/.558

While others had flashier showings, Walker was the talk of the AFL. He handled himself with poise while flashing a superstar ceiling – both by the traditional eye-test and via Statcast measurables. He likely could hold his own in the Majors as soon as next season. The Cardinals have been working on shifting him to the outfield in deference to Nolan Arenado. The main element lacking in Walker’s development is the easiest to supply – experience. He needs more opportunities to face and adjust to star-caliber pitching. Along the way, he’ll likely develop into a regular All-Star candidate.

Matt Mervis, 24, 1B, CHC (AAA)
AFL: 68 PA, 6 HR, 2 SB, .262/.324/.590

Of AFL participants (excluding Joey Wentz), Mervis probably has the best chance to open 2023 in the Majors. Including the regular season, he hit 42 home runs in 646 plate appearances this year. Remarkably, especially for the AFL home run leader, he fanned just eight times (11.8% K%) this fall. He also improved his strikeout rate continuously throughout the regular season. He began in High-A, where he recorded a 24.1 percent strikeout rate. That dropped to just 20.0 percent in Double-A and 14.6 percent in Triple-A. The low rate at his final stop coincided with an 8.7 percent swinging strike rate – far better than the league average. If Mervis can continue to avoid strikeouts while tapping into his power, he’ll have a bright future as a mid-lineup left-handed slugger.

Five More

Edouard Julien (23): Julien has been covered ad nauseum in this column. No prospect did more to further their claim to a future Major League role this fall. He’ll almost certainly be protected from the upcoming Rule 5 Draft. Julien’s combination of discipline, contact, sneaky pop, and sneakier baserunning are the traits of a regular. He still needs to settle into a position defensively – an issue that has arisen a few times in the Twins recent past (Luis Arraez, Jose Miranda, Nick Gordon).

Evan Reifert, TBR (23): Reifert allowed a hit in his final inning of work, closing out the season with 11.2 innings, 40 batters faced, one hit allowed, four walks, and 25 strikeouts. Despite a relatively low inning total, he had the second-most strikeouts. The showing will help put him in consideration for a Major League role next season. The Rays have a crammed 40-man roster, and Reifert isn’t Rule 5-eligible until next offseason.

Tyler Hardman, NYY (23): A developing slugger with potent pop, Hardman is coming off Player of the Week honors. Overall, he posted a .325/.373/.662 line in 83 plate appearances. Of qualified hitters, he had the fourth-best OPS. Contact and inconsistent defense at the hot corner hold him back from appearing on prospect lists.

Nick Gonzales, PIT (23): Gonzales dropped from the spotlight due to injury and flawed performance. His AFL stint allowed him to build on a solid first showing in Double-A. In both settings, he succeeded without truly impressing. Whiffs remain an issue for a second baseman who is heavily dependent on his offensive output.

Francisco Morales, PHI (23): Morales is an interesting AFL participant because the Phillies have already burned two of his option years. They’re likely assessing if he should remain on the roster at all. He was one of four pitchers to throw 10 or more AFL innings without allowing an earned run. He recorded 17 strikeouts with only four hits allowed in 10.2 innings. He also issued seven free passes. Those walk issues have haunted him on a regular basis.