American League Rookie Roundup: X-Factors for the Second Half Playoff Push

As teams gear up for the stretch run to the postseason, these rookies have the potential to significantly impact the playoff race.

Kjerstad reacts after hitting a double during the fourth inning against the Texas Rangers at Oriole Park at Camden Yards. / Reggie Hildred-USA TODAY Sports

Welcome to the Rookie Roundup, a weekly look-in on baseball’s best and most interesting first-year players. We’re back from the All-Star break and ready to dive in on which rookies will make the most substantial contributions for American League contenders during the season’s second half.

The week of the MLB All-Star Game always signals the lull of the sports calendar. Even in an Olympics year, we were bereft of much to talk about in the sports realm last week (there’s a reason the ESPYs are annually held in mid-July).

But with the return of games Friday, the daily grind of the baseball season resumed its march toward October. And the quiet calm of a few days off serve as prelude to the trade deadline and dog days of summer as teams jockey for playoff position.

In the American League, the standings offer plenty of intrigue. Entering play Monday, no division leader held an advantage of more than five games, while six teams in the wild-card race were within six games of each other. That creates a compelling dynamic ahead of the trade deadline to see which teams opt to make a push for this season, and which stand pat or go the sellers’ route with an eye toward 2025 and beyond.

But trade talk is for another time. Instead, let’s take a look at the AL’s three first-place teams—plus our top two wild-card squads—and see which rookies will prove to be the most impactful X-factors for the stretch run.

Heston Kjerstad, OF, Baltimore Orioles

On a roster loaded with young hitters, you wouldn’t be blamed for forgetting about Kjerstad. The No. 2 pick in the 2020 draft struggled in his first stint in the majors this season, going 2-for-14 in a seven-game stretch before getting optioned back to the minors. Baltimore called him up on June 24, and he’s been on a tear ever since. In 16 games since his latest promotion, Kjerstad has posted a .350/.447/.625 slash line with three homers.

Regular playing time can be hard to come by given the Orioles’ deep stable of position players, so Kjerstad will need to keep up the pace in order to get more plate appearances. But with fellow rookie Colton Cowser continuing to struggle offensively, perhaps Kjerstad will get more opportunities as Baltimore attempts to fend off the competition in the American League East.

Hunter Gaddis and Cade Smith, RPs, Cleveland Guardians

Emmanuel Clase rightfully gets credit as one of the game’s premier closers. But the reason the Guardians lead the majors in bullpen ERA (2.56) and fWAR (5.1) is because of their depth, and rookies Gaddis and Smith are key contributors there.

Smith ranks eighth among all relief pitchers with a 36.4% strikeout rate, while Gaddis has the third-lowest WHIP (0.73) thanks to a miniscule 4.1% walk rate. Between Gaddis, Smith, Tim Herrin and Scott Barlos, Cleveland has an embarrassment of riches comprising its bridge to getting Clase the ball in the ninth inning.

Spencer Arrighetti, SP, Houston Astros

For a Houston rotation that’s dealt a litany of injuries, Arrighetti has filled a much-needed void for a team that finds itself in first place in what’s been baseball’s weakest division. After amassing 293 strikeouts over 231 1/3 minor league innings from 2022 to ‘23, Arrighetti debuted in April and has had his fair share of ups and downs. The righthander has stabilized as of late, posting a 3.68 ERA over his last four starts with 28 strikeouts and just nine walks. Arrighetti has already logged 80 innings this season after tossing a career high 124 2/3 last season, so we’ll see if Houston opts to limit his outings down the stretch.

Austin Wells, C, New York Yankees

A first-round pick by the Yankees in 2020, Wells got a brief 16-game stint in the majors last year and has now progressed to claiming a share of New York’s starting catcher duties. Wells has seen his bat pick up the pace over the past month, posting a .246/.369/.493 slash line since June 6. He’s been pushed into an everyday role with Jose Trevino currently on the injured list, with 11 starts in New York’s last 14 games—a stretch that includes his 3-for-5 performance on Monday that saw Wells blast his seventh homer of the season.

AUSTIN WELLS LAUNCHES IT FOR THE LEAD! 🚀 pic.twitter.com/RcFevWnxLn

— YES Network (@YESNetwork) July 22, 2024

Wells’s greatest strength offensively is his patient eye. He owns a 12.8% walk rate to boost his offensive floor, and his potential at the plate looks to have an even higher ceiling given his meager .250 BABIP. While he’ll likely shift back into a timeshare situation once Trevino returns, he’ll remain a key contributor for a lineup that needs its supporting cast to step up and support another historic season from MVP favorite Aaron Judge.

Brooks Lee, 3B, Minnesota Twins

It’s tough to sugarcoat Royce Lewis’s latest trip to the injured list, but his absence has created an opportunity for Lee, whom the Twins selected with the No. 8 pick back in 2022. The 23-year-old posted an .844 OPS in the minor leagues before getting called up on July 3 to replace Lewis in the lineup.

Lee came out of the gates hot, with 12 hits (including two homers) in his first eight games before cooling off a bit. The oft-injured Lewis has resumed running and taking batting practice, so perhaps he’ll be back in the lineup sooner rather than later. But given his history, it would be prudent for Minnesota to keep Lee ready for a larger role down the stretch as the team looks to chase down the Guardians and defend its American League Central crown.