Feb 24, 2024; Port Charlotte, Florida, USA; Tampa Bay Rays third baseman Junior Caminero (13) catches a fly ball in the second inning of a spring training game against the Atlanta Braves at Charlotte Sports Park. Mandatory Credit: Jonathan Dyer-USA TODAY Sports This list of top candidates for a breakout season in Major League Baseball is an eclectic group.
It includes a pair of rookies from each league, along with one of the top prospects from a year ago who stands to make a major improvement in 2025.
The list also includes an outfielder who just needs a chance to play every day to join the elites, and a relief pitcher turned starter who debuted seven years ago. All of them stand a good chance to be big-time performers that fans will be talking about this season.
Junior Caminero, third base, Tampa Bay Rays
Caminero already has 213 career plate appearances, so he’s not eligible for AL Rookie of the Year. But his major league experience makes for a strong foundation that sets up big breakout potential in 2025 at age 21-22.
Caminero got a taste of the majors two years ago, just after he turned 20 years old. Coming in as a top 3-4 consensus overall prospect in 2024, he put up a .248/.299/.424 line with six home runs, 11 walks and nine doubles in 177 plate appearances. A solid performance relative to his age that translates to perhaps 5% better than league average when adjusted for home ballpark and league contexts.
Projection systems vary, but an optimistic one at FanGraphs says Caminero will hit 30 home runs and be worth 4.3 fWAR, which would have made him the third-most valuable third baseman in the league in 2024. That might be a stretch this season, given the unpredictability of youth. Plus, we’ll have to see what effect playing home games at Steinbrenner Field in Tampa will have. Its dimensions, which duplicate Yankee Stadium, are more appealing to left-handed pull hitters, but the right-handed-hitting Caminero went to the opposite field more than the league average in 2024.
Jack Leiter, right-handed pitcher, Texas Rangers
Mar 8, 2024; Surprise, Arizona, USA; Texas Rangers starting pitcher Jack Leiter (71) pitches against the Kansas City Royals during the first inning at Surprise Stadium. credits: Joe Camporeale-USA TODAY Sports A son of former major league lefty Al Leiter, the younger Leiter came to camp ready to show he was better than his first big-league results in 2024. Leiter’s performance in Grapefruit League play, along with injuries to right-hander Jon Gray and left-hander Cody Bradford, have made him a good bet to open the season in the Rangers’ starting rotation. He’s still considered a rookie.
Both of Leiter’s fastballs (a four-seamer and a sinker, which is a new pitch for him) have reached 99-plus mph this spring, and he’s sitting at 98 mph on all of his fastballs. He’s also refined his changeup (called a “kick change”), and it has been nearly unhittable, with batters going 1-for-14 against it with a 50% strikeout rate, along with a 31% swing-and-miss rate, on 51 total pitches.
It’s how scouts envisioned Leiter when the Rangers picked him second overall from Vanderbilt in the 2021 MLB Draft. He was a consensus top 20-25 prospect by the following season, but Leiter didn’t succeed in his first pro season after the Rangers started him at Class AA, posting high ERAs by giving up too many walks and home runs. It’s something he’ll still have to refine. But, for the patient, Leiter has been showing signs of improvement all along.
By mid-2024 at Class AAA, he was getting closer to expectations. A call-up to the Rangers did not result well over two stints (9.84 ERA, 44 hits allowed, seven homers, 17 walks and 31 strikeouts in 35 2/3 innings), but Leiter has been making adjustments. Sometimes, getting better just takes longer than is considered ideal.
Matt Wallner, outfielder, Minnesota Twins
Sep 7, 2024; Kansas City, Missouri, USA; Minnesota Twins left fielder Matt Wallner (38) catches the ball in foul territory in the third inning against the Kansas City Royals at Kauffman Stadium. Mandatory Credit: Peter Aiken-Imagn Images Wallner has posted impressive rate stats over two half-seasons with the Twins. In 580 career plate appearances (mostly in 2023-24), Wallner is hitting .251/.366/.500 with 29 home runs, 31 doubles and 58 walks, earning a total of 4.0 bWAR.
A left-handed swing who recently turned 27 years old, Wallner has yet to make himself more than a strong-side platoon player. But it’s been in the works this spring, with manager Rocco Baldelli giving Wallner time against left-handed pitching, even as the Twins’ leadoff hitter.
Wallner hasn’t hit lefties in the majors so far, but he did in the upper minors in 2022-23, posting slugging percentages north of .600 in those splits. All things considered, Wallner is the Twins’ best defensive right fielder, and they’re better when he stays in the game and isn’t substituted midway because of a possible platoon advantage for one at-bat. Given the ability he has shown against lefties before, and the major league success he’s had part time, a full-time Matt Wallner seems poised for a 35- or 40-home run season.
Matt Shaw, infielder, Chicago Cubs
A teammate, Pete Crow-Armstrong, got a lot of attention for his gaudy Cactus League numbers, but Shaw as a rookie has a chance to make a bigger impact on offense while playing third base.
Considered a consensus top-30 or so prospect the past two seasons, Shaw ranked No. 14 overall by Keith Law coming into camp. Before getting a brief taste with the big team at the end of 2024, Shaw hit .279/.373/.468 with a 17.5% strikeout rate in Double-A, and followed it with a .298/.395/.534 line with a 19.7% strikeout rate at Triple-A. Pretty good for 23 years old.
A natural shortstop, Shaw’s best seasons probably will come once he masters third base and improves his power stroke. But he should be above average from the jump, and has a strong chance to be a .300 hitter with 17-20 homers — which would make him a leading contender for NL Rookie of the Year.
Clay Holmes, right-handed pitcher, New York Mets
Feb 22, 2025; Port St. Lucie, Florida, USA; New York Mets pitcher Clay Holmes (35) walks in from the bullpen area before the game against the Houston Astros at Clover Park. Mandatory Credit: Jim Rassol-Imagn Images The New York Yankees no doubt enjoyed having slugger Juan Soto around to help them reach the World Series a season ago. Soto didn’t come to the Bronx for free, though, with right-hander Michael King a big part of the trade package with San Diego. Mostly a reliever with the Yanks, all King did was turn into one of the best starting pitchers in the league with the Padres.
Lightning might strike again, in a sense, with Holmes moving across town as a free agent to join Soto and the Mets. Holmes never made a start with the Yankees, but he made four with the Pittsburgh Pirates as a rookie and 114 more in the minors before they turned him into a reliever. At nearly 32, he’s easily the oldest and most experienced player in this group. He posted a 2.69 ERA with 238 strikeouts in 217 2/3 innings exclusively as a reliever during four years with the Yankees, but he’s betting on himself (as are the Mets) as a starting pitcher.
Holmes has gotten enough value from the entirety of a three-pitch mix (sinker, slider, sweeper) to be effective as a reliever, but his breaking pitches have become his go-tos. Holmes has been working on adding a cutter and a changeup this spring, but it’s to be seen if he carries everything into the regular season. If he expands his arsenal, it would be a similar attack plan to what Seth Lugo used in going from an effective reliever to one of the top starters in the AL. Assuming he handles the physical stress of being a starting pitcher, Holmes has a chance to follow the recent success of King and Lugo.
