Every season features its share of impressive breakouts -- some that were long forecasted and others that come out of nowhere.
In 2021, we saw Vladimir Guerrero Jr. -- the son of a Hall of Famer and a former No. 1 overall prospect -- erupt for 48 homers, 111 RBIs and a .311/.401/.601 slash line. We also saw former 13th-round Draft pick Cedric Mullins go from a 72 OPS+ over his first three seasons to a 135 OPS+, 30 homers and 30 steals in Year 4.
With an eye on the 2022 campaign, MLB.com convened five MLB.com writers to pick the hitters who might make a similar jump this season. Here are the selections:
Jarred Kelenic, OF, Mariners
Key number: .383 xwOBA after Aug. 31
A potential five-tool stud, Kelenic surged up prospect rankings after being traded from the Mets to the Mariners in the December 2018 deal that brought Edwin Díaz and Robinson Canó to New York, peaking at No. 4 overall, according to MLB Pipeline, before making his much anticipated MLB debut last May.
Less than a month later, he was back in the Minors, having hit .096/.185/.193 over his first 23 games. Things didn’t get much better when Kelenic returned to the Mariners after the All-Star break, but Seattle stuck with him and something finally clicked for the 22-year-old in September.
Kelenic started making more contact, lowering his whiff rate to 21.4% (29.5% through Aug. 31) and his strikeout rate to 24.6% (29.7% through Aug. 31), and his power began to emerge as well. From Sept. 1 through the end of the regular season, Kelenic posted an 18.4% barrel rate, ranking 13th in the Majors (min. 50 batted balls). His expected wOBA -- which is based on quality of contact, strikeouts and walks -- in that span was .383, more than 100 points higher than the .277 xwOBA he posted through Aug. 31. Now that he’s tasted some success at baseball’s highest level, Kelenic is poised to take the next step toward stardom.
-- Thomas Harrigan
Jazz Chisholm Jr. -- 2B, Marlins
Key number: Ranked in top 10% in barrel rate + sprint speed through May 31, 2021
Chisholm’s .728 OPS (96 OPS+) and 2.5 oWAR posted by the end of 2021 sold him short of the potential seen from Miami’s young stud earlier in the season. Chisholm roared out of the gate as one of the game’s most electric young stars, standing alongside names like Ronald Acuña Jr., Byron Buxton, Shohei Ohtani and Mike Trout on the short list of players that ranked in the 90th percentile or better in Statcast’s barrel (ideal combinations of exit velocity and launch angle) and sprint speed metrics. It’s natural to wonder whether Chisholm’s assorted injuries to his hamstring, ankle and shoulder threw off his momentum as the season progressed, though that OPS hovered near .900 even into the second week of June.
Chisholm was on the roster for Miami’s unexpected postseason appearance in 2020, and so it’s easy to forget that the 24-year-old still hasn’t played a full season’s worth of games in the big leagues. Here’s a bet that Chisholm’s flash of elite power-speed brilliance seen last spring will return and sustain, now that he has a better sense of how long and grueling a full season will be. Don’t forget: this man took Jacob deGrom’s fastball to the upper deck last year.
-- Matt Kelly
Dylan Carlson -- OF, Cardinals
Key number: 40.6 sweet-spot rate
A year ago, there was some buzz around a young Cardinals outfielder who possessed both the pedigree and tools to emerge as a bona fide big leaguer. It happened, except the bonkers breakout belonged not to Carlson but to Tyler O’Neill, who posted a 150 OPS+, won a Gold Glove and finished eighth in the NL MVP voting practically out of nowhere.
It just might be Carlson’s turn in 2022. MLB Pipeline’s No. 13 overall prospect a year ago, the 2016 first-rounder held his own in his first full campaign -- in fact, Carlson came in third place in the NL Rookie of the Year race, but clearly was overshadowed by O’Neill’s stellar season. And while his .266/.343/.437 (117 OPS+) slash line was solid, it wasn’t exactly a “breakout.” Carlson did, however, record a 40.6% sweet-spot rate, which ranked seventh best in MLB, and his second-half stats (.505 SLG and .847 OPS) provided evidence that there’s more pop to come. After proving he could handle The Show as a rookie, look for the 23-year-old switch-hitter to take it up a notch this time around.
-- Jason Catania
Alex Kirilloff -- OF/1B/DH, Twins
Key number: .367 expected wOBA in 2021
In an alternate timeline, 2021 was Kirilloff’s breakout season. Unfortunately, a right wrist injury got in the way. The problem sent Kirilloff to the injured list for 16 games in May, continued to bother him after he returned and ultimately led to season-ending surgery for a ligament tear in July. Kirilloff’s numbers in the 59 games he played weren’t great -- he hit .251/.299/.423 for a near-average 98 OPS+ -- but they were pretty impressive for a 23-year-old rookie whose balky wrist was affecting his sweet left-handed swing.
Even then, Kirilloff’s bat was significantly better than it looked from the raw numbers. His quality-of-content metrics were well above average, while his strikeout rate was below the MLB-wide rate. His .367 xwOBA -- which factors in quality of contact, strikeouts and walks -- far outpaced his actual wOBA of .307 and put Kirilloff in roughly the 85th percentile of MLB hitters (above sluggers Nelson Cruz, George Springer and Giancarlo Stanton). That bodes well for 2022, when Kirilloff should take off, health permitting. Where and how well Kirilloff plays defensively are legitimate questions, but it’s also quite possible that the bat is good enough for it not to matter much.
-- Andrew Simon
Ke’Bryan Hayes – 3B, Pirates
Key number: 55.4% hard-hit rate in 2020
After a stellar-but-brief debut in 2020, ‘21 was supposed to be Hayes’ breakout season. But he injured his left wrist in the Pirates’ second game of the season, missed two months, and never quite hit his stride offensively before wrist soreness ended his season in late September. Only Hayes can speak to whether the wrist bothered him in the 96 games he did play – or the 94 after the injury, to be precise – and players never want to cede to excuses. But the differences in his contact quality provide some clues as to whether it hampered him.
In 2020, albeit a shortened season and a mere 24-game debut for Hayes, he had a 55.4% hard-hit rate, well above the MLB average, which was 37.5% in ‘20 and 38.7% in ‘21. This past season, his hard-hit rate dropped nearly 10 percentage points, to 45.8%. There is, of course, an expectation that the brief 24-game sample in 2020 might not reflect his entire career, but with the wrist injury context, the true raw power for Hayes likely lies somewhere in between. It isn’t quite fair to discount 2021 entirely, but for a young player who dealt with injury, there’s as much reason for optimism here as there was a year ago.
-- Sarah Langs