Who will be this postseason's breakout star?

October 7th, 2021

It would have been nearly impossible for anyone to predict what Randy Arozarena pulled off last October.

With only 42 career regular-season games under his belt entering the 2020 postseason, the Rays outfielder hit a ridiculous .377 with a 1.273 while hitting an MLB postseason record 10 home runs in 20 games -- a number that surpassed his career home run total to that point (eight).

This year, however, we're going to try to uncover the next player poised for postseason stardom before it happens. Of course, that's not to say these players will have Arozarena-esque performances -- his postseason was historic in many ways -- but these under-the-radar players are certainly worth keeping a close eye on over the next few weeks.

Here's a look at six players selected by MLB.com reporters who could break out this October:

, RHP, Rays
Key stat: 35.3% whiff rate

Tampa Bay was far enough ahead in the AL East that there wasn’t much noise when it called up Baz -- the last piece and player to be named later in the masterful 2018 trade that also brought Tyler Glasnow and Austin Meadows over from Pittsburgh. But in retrospect, Baz’s arrival should have been a bigger deal. Sure, it’s only three starts, but those outings were dominant enough to convince the Rays to turn to their top prospect for Game 2 of the ALDS. The 22-year-old carved up the Blue Jays and Marlins in his first two outings, starting his Major League career by striking out George Springer and Vladimir Guerrero Jr. in his first inning, then humming on from there with 18 strikeouts and just three runs allowed across his first 13 1/3 big league innings.

Any rookie can start hot out of the gate, but it’s the way that Baz has delivered on the scouting report and made big leaguers look silly that makes him an arm to watch this October. His fastball scrapes triple digits with elite spin and vertical “rise,” and the heat sets up a pair of breaking balls that have combined for a 43.9% whiff rate in The Show. Baz could join Shane McClanahan and Drew Rasmussen to form an extremely young but talented postseason rotation for the Rays. He could also emerge as a bullpen force as the postseason goes on and lean heavily on the fastball-slider combo (the Rays will never be conventional with their pitching usage regardless). Whenever he steps on the mound, this kid has electric stuff made for October. -- Matt Kelly

, LHP, White Sox
Key stat: 73.5% ground-ball rate since 2019

The Chicago bullpen has bigger names -- arguably the game’s top closer this year (Liam Hendriks) and a potential Hall of Famer (Craig Kimbrel). It has harder throwers, too, in young guns Michael Kopech and Garrett Crochet. All of those guys figure to play key roles, but don’t overlook Bummer and his relatively quiet brilliance (2.63 ERA in 129 games since 2019). The lefty has a strong claim as MLB’s top ground-ball artist thanks to his plummeting sinker, and you can’t give up a big home run on a grounder. Bummer also has ramped up the usage of a slider that has elite movement and a whiff rate above 50%.

Between the worm-burners and the missed bats, Bummer has allowed a barrel (the most damaging sort of contact) more often per plate appearance than only the Giants’ Tyler Rogers over the past three seasons. Only four pitchers -- all big names, including Hendriks -- have posted a better expected wOBA. You can bet that if the White Sox make a deep run, Bummer will lock down quite a few high-leverage outs along the way. -- Andrew Simon

, 1B/OF, Giants
Key stat: .504 xSLG vs. right-handed pitchers

One of the reasons the Giants were able to exceed expectations in winning 107 games this season was because they’ve gotten production from all corners of the roster. San Francisco acquired Wade from the Twins for reliever Shaun Anderson before the season and the team has watched him blossom into a productive platoon bat, slashing .253/.326/.482 (117 OPS+) with 18 homers in 381 plate appearances -- 339 of them against right-handed pitchers.

The 27-year-old has become even more important to the Giants’ championship pursuits after Brandon Belt suffered a left thumb fracture that’s expected to sideline him through at least the NLDS. With Belt out, Wade could slot in as the Giants’ starting first baseman against right-handed pitchers during the postseason. He’s certainly someone who shouldn’t be overlooked. Wade’s .504 xSLG vs. right-handed pitchers is the 17th-highest mark among 104 left-handed batters with at least 250 plate appearances in those matchups this season. Wade also has shown a flair for the dramatic, collecting 19 go-ahead hits (seven homers) and recording a 1.560 OPS in high-leverage situations. -- Thomas Harrigan

, 2B/OF, Dodgers
Key stat: .967 OPS since returning from Triple-A on Sept. 10

It’s easy to forget about Lux, who entered the season with a chance to establish himself as a young star but was sent to Triple-A after the Dodgers traded for Trea Turner. But with a need for more outfield depth, the club called Lux back up in early September and gave the second baseman a shot in the outfield. Following a few early defensive hiccups, he’s looked pretty good out there -- he even nearly made a spectacular running catch before smashing into the center-field wall in a Sept. 29 game at Dodger Stadium. Add to that his improvement at the plate since his return from the Minors, and you’ve got the makings of an unexpected postseason hero if the right scenario presents itself.

We’re all pretty used to seeing unexpected heroes for the Dodgers, usually in the form of a rookie callup who hits a walk-off homer or something. But in Lux’s case, we’re talking about the 20th overall pick in the 2016 MLB Draft, a guy who has been groomed for the big moment. Lux is banking on the Dodgers’ penchant for plugging players in at all sorts of positions thanks to their luxury (Lux-ury?) of depth and defensive versatility. And with his more aggressive approach at the plate paying off, don’t be surprised if Lux becomes the latest in a long line of October heroes for Los Angeles. -- Manny Randhawa

, OF, Brewers
Key stat: 50.1% first-pitch swing rate

García was one of the Brewers’ most consistent offensive contributors throughout this season, leading the club with 29 homers and 86 RBIs. Much of his success emanates from his aggressiveness. His 50.1% first-pitch swing rate was second in MLB among players with at least 300 plate appearances, behind only Corey Seager (53.4%). Swinging at the first pitch is all well and good, but it’s notable for García because of the success it leads to. He hit .353 and slugged .671 with seven homers when putting the first pitch in play this season.

García isn’t among the game’s absolute speedsters or sluggers, but he also features an impressive power-speed combination. He was one of just eight qualifiers in 2021 to rank in at least the 75th percentile in hard-hit rate and at least the 85th percentile in sprint speed. He’s the type of player who could carry the Brewers’ offense while Brandon Woodruff, Corbin Burnes and Freddy Peralta lead the pitching staff in October. -- Sarah Langs

, OF, Giants
Key stat: .297/.400/.568 slash line in 2020

Don't let it slip that Yastrzemski spent the first half of the season as the Giants' No. 2 hitter (with the occasional stint in the leadoff spot or three-hole). Now, it's definitely been a down season for him, so he kind of became the forgotten man behind the resurgent seasons of Giants veterans like Buster Posey, Belt, Brandon Crawford and Evan Longoria. But the all-around hitter who showed signs of greatness as a rookie and then vaulted into the MVP conversation in 2020 is still in there. His slash line from last year is a reminder that he has a complete skill set when he's hot -- Yastrzemski has the ability to hit for contact, get on base and slug. That is the type of player you want in the lineup in October, when every at-bat is that much more competitive. Yaz is going to have some big ones for the Giants this postseason. -- David Adler

, RHP, White Sox
Key stat: 8 starts with double-digit strikeouts this season (T-3rd most in MLB)

Lance Lynn was the AL Cy Young Award conversation for most of the season. Lucas Giolito received a share of AL Cy Young votes each of the past two seasons and was once again solid for the White Sox in 2021. Carlos Rodón threw a no-hitter and had a 2.37 ERA this season. But with Rodón dealing with some left shoulder soreness that has his status up in the air, the White Sox may need Cease to solidify the rotation -- and he's more than capable.

The right-hander cruised to a 2.98 ERA through his first 10 starts this season, but he then put up a 5.44 ERA over his next 10. Cease rediscovered his early-season form down the stretch, allowing one run or fewer in five of his final seven outings. Overall, Cease struck out 226 batters over 165 2/3 innings this season and his 31.9 K% ranked fifth in the Majors among pitchers with at least 150 innings, trailing only four Cy Young Award candidates: Burnes, Max Scherzer, Gerrit Cole and Robbie Ray. -- Paul Casella