MLB rosters expanded to 28 on Tuesday, Sept. 1, which meant a mass influx of minor leaguers being promoted to the majors — many for the very first time. While not every last-second promotion generates excitement, there are a handful of MLB newcomers with a chance to genuinely impact the postseason race. There is sure to be more late call-ups in the coming days and weeks, too. Nothing is set in stone at this stage.
Let's focus on four names, on four Wild Card teams, whose impact could mean the difference between a rousing postseason berth or an October spent on the couch.
UTIL Ben Ross, Minnesota Twins
The Twins called up FanSided's No. 4 overall prospect Walker Jenkins a couple days ago, so we will exclude him as the "obvious" answer to this prompt. But Minnesota did use the Sept. 1 roster expansion to call up utility infielder Ben Ross, MLB Pipeline's No. 13 Twins prospect.
The 25-year-old Ross lacks standout traits, but he put up 15 homers with an .810 OPS in Triple-A this season. Ross is especially effective against left-handed pitching, which addresses a crippling weakness for this Twins team. Minnesota has faded from the postseason conversation in recent days, but there's a month left in the regular season and the Twins are a whole 3.5 games back. There is still ample time to reverse their fortunes.
In addition to his platoon-caliber bat, Ross displays excellent glovework at a variety of positions. He's comfortable in the middle infield; he can step out in center and cover ground. The Twins can move him around comfortably, allowing them to really maximize his situational value at the plate. Expect a lot of pinch-hit opportunities for Ross down the stretch, in addition to the occasional start.
3B Sean Keys, Toronto Blue Jays
Sean Keys made his Blue Jays debut in July, playing six games before an equally swift demotion. He's back for the stretch run, however, with the chance to add some lefty pop to a Toronto lineup that skews right-handed.
Keys went 6-for-36 with a homer in his first MLB stint, but he has outright dominated in the minors, thwacking 14 homers with a 1.044 OPS in 51 Triple-A games. He hit seven homers in August alone, so he's riding a wave into the Toronto clubhouse. Keys generates extremely hard contact and takes a disciplined approach at the plate. Now that he has had time to adjust since his first taste of major league pitching, there's reason the bat can translate.
The only challenge: actually getting on the field. With Kazuma Okamoto and Vladimir Guerrero Jr. entrenched at the infield corners, and with George Springer soaking up DH reps, Keys is currently pegged as more of a platoon option and situational bat. He's not much of a defender either, so he needs to hit to stick.
LHP Luis De León, Baltimore Orioles
Baltimore's rotation has been a sore spot for years now, and this season was not much of an improvement. And yet, the offense has caught a spark over the last month and the O's are only a half-game behind Cleveland for the final American League Wild Card spot.
Realistically, it's too late in the campaign for the 23-year-old Luis De León to crack the Orioles rotation. That is a 2027 project; in fact, Baltimore already moved De León to the bullpen in Triple-A in anticipation of this exact moment. The O's want him to come in for an inning or two at a time and throw his best stuff.
It's hard to argue with the strategy. De León has a mean fastball-slider combo, but he has struggled with command. The best way to mitigate such risks are by streamlining his workload and just letting him go all-out in concentrated bursts, rather than tasking De León with walking a starter's tightrope for five-plus innings every week.
Baltimore's bullpen is not especially talent-rich right now, so there's a nonzero chance De León is quickly earning high-leverage appearances.
C Ethan Salas, San Diego Padres
The Padres called up catcher Ethan Salas, their top prospect — and FanSided's No. 42 prospect. After an abysmal, injury-plagued 2025 campaign in Double-A, the Padres still promoted him aggressively this season. As they say, fortune favors the bold. In 24 Triple-A games before his MLB call-up, Salas hit .326 with a .949 OPS.
It seems like Salas has figured it out at the plate after some doubt in the early years of his development. The Padres, however, are basically hoping Salas can find a productive middle ground between Freddy Fermín (elite defense, M.I.A. at the plate) and Luis Campusano (absymal defense with an .844 OPS). He does not need to rake at the plate; Salas needs only to provide passable offensive production to potentially earn the everyday job in time for October.
Salas' offensive explosion has been a pleasant development, and in no doubt expedited his path to the majors. But the reason Salas is so highly regarded is his elite defense and game management skills behind home plate. Framing, blocking, arm strength and IQ — Salas checks all the important boxes for one of baseball's most challenging and essential positions. If he can hit, too, San Diego will be riding high into October.
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