10 MLB September Call-Ups Who Could Shape the Pennant Races

Rules changes mean major league teams no longer add five, 10 or 15 players to their active rosters on Sept. 1. Now, they’re limited to two. But a number of teams have promoted rookies, activated injured players and even used the waiver wire to make what they hope are the finishing touches to their respective rosters.

Here are 10 players who could impact the pennant races — and possibly beyond.

Harry Ford, C, Seattle Mariners

In a different year, the Mariners might have dealt Ford at the trade deadline, considering he’s blocked by Cal Raleigh (and even Mitch Garver) behind the plate. A top-100 overall prospect, he’s a 22-year-old bat-first catcher who hit .283/.408/.460 with 16 homers at Triple-A. Ford could give the Mariners a lift at DH in their postseason run if Jorge Polanco slid over to second base instead of rookie Cole Young.

Carter Jensen, C, Kansas City Royals

The Royals traded Freddy Fermin to the Padres in August as a precursor to promoting Jensen, who at 22 batted .290/.377/.501 with 20 homers, 20 doubles and 60 walks between Double-A and Triple-A. With the way the Royals use Salvador Perez, there’s room to add Jensen’s bat to the lineup most days.

Luis Garcia, RHP, Houston Astros

A key member of the Astros’ rotation in 2021-22, Garcia was sidelined with Tommy John surgery early in 2023 and is just getting back now at age 28. His numbers at Triple-A (2.60 ERA, 20-4 K-BB ratio in 17 1/3 innings) were encouraging, and he could help the Astros in their playoff push.

Sal Stewart, INF, Cincinnati Reds

Still just 21, Stewart started at first base and went 1-for-3 with a run scored in his debut Monday. A first-round pick (32nd overall) in 2022, he has improved his hitting each year as a pro. Stewart batted .309/.383/.524 with 20 homers, 17 stolen bases, a 9.3% walk rate and 15.6% strikeout rate between Double-A and Triple-A.

Michael Kopech, RHP, Los Angeles Dodgers

Kopech was limited to seven innings before September because of shoulder and knee injuries, but he’s been effective in relief since joining the Dodgers at the 2024 trade deadline. He could be a big addition all over again.

Jackson Merrill, CF, San Diego Padres

Merrill spent three stints on the injured list, most recently with a sprained ankle, and it undoubtedly affected his production at the plate. If he can put together a push in the final 3 1/2 weeks and resemble his rookie season — when he hit .292/.326/.500 with 24 homers and 16 steals — the Padres will be much more dangerous come playoff time.

Ha-Seong Kim, INF, Atlanta Braves

Claimed off waivers from the Tampa Bay Rays, Kim is currently on the injured list and won’t be helping the Braves in a pennant race this season. But he does give them an option for the middle infield in 2026 if he picks up a $16 million player option.

Joey Ortiz, SS, Milwaukee Brewers

Injuries have limited Ortiz in his sophomore season, but if he’s cleared from his left hamstring strain and other ailments, he’ll be able to bolster the Brewers for their final postseason push.

Ryan Yarbrough, LHP, New York Yankees

Yarbrough was an effective opener and bulk option for the Yankees, posting a 3.90 ERA with 49 strikeouts in 55 1/3 innings before an oblique strain sidelined him in June.

Walker Buehler, RHP, Philadelphia Phillies

As a Hail Mary, the Phillies signed Buehler, who just turned 31, and sent him to Triple-A after the Boston Red Sox cut ties with him in late August. Buehler is playoff-eligible and has a 3.04 ERA with 114 strikeouts in 94 2/3 career postseason innings, including a memorable World Series Game 3 victory with the Dodgers in 2024. Injuries, for the most part, have derailed consistent success.