Updated Monday, August 31, 2026. Rosters expand tomorrow.
On September 1 every active roster in baseball goes from 26 players to 28, and the pitcher limit rises from 13 to 14. That is the whole of modern roster expansion — two spots, not the fourteen older fans remember.
Which means the interesting question isn’t who deserves a call-up. It’s who fits into two slots that most contenders have already earmarked for bullpen arms.
The Constraint Nobody Mentions
Anyone added on September 1 has to already be on the 40-man roster. A club with a full 40 must clear a spot before promoting anybody — designating someone for assignment, or moving a player to the 60-day injured list.
That friction is why the two open spots frequently go to players already cycling on and off the roster rather than the best name in Triple-A. A star prospect who isn’t on the 40 requires a corresponding move that costs the organisation something real.
Candidates Worth Watching
| Player | Org | The case, and the obstacle |
|---|---|---|
| Josue De Paula | Dodgers | MLB’s No. 6 prospect, 21, hitting .315 at Triple-A Tulsa with 25 homers. The problem is fit — with Ohtani at DH he is a corner outfielder only, which means sitting a veteran. |
| Gage Wood | Phillies | No. 26 pick in the 2025 draft with an electric fastball-curveball pair. Andrew Painter has settled the rotation, so Wood’s path is the bullpen — where Philadelphia has a genuine need. |
| Patrick Clohisy | Braves | Hitting .357/.440/.512 in 37 Triple-A games with 21 steals. Can play all three outfield spots, which is exactly the bench profile these two slots reward. |
| Ethan Salas | Padres | Turned 20 in June, hitting .292/.368/.448 with nine homers and recently promoted to Triple-A. An elite defensive catcher — and a third catcher is a classic expansion add. |
| Demetrio Crisantes | Diamondbacks | Swinging it well at 21, but blocked — Ketel Marte and Nolan Arenado occupy his positions. |
Contenders and Sellers Use the Same Two Spots Differently
A team fighting for a playoff seed almost always spends both slots on pitching depth and roster insurance: one more reliever to protect the high-leverage arms, and one bench piece, often a third catcher, so the manager can pinch-hit without stranding himself.
The goal is simple — stop the sixth and seventh innings from consuming the same three arms every night.
A team out of the race does the opposite. Washington, well outside the wild card picture, has every reason to use September as an audition for 2027. So do the Rockies, Giants, Angels and Athletics.
It Actually Matters in October
The temptation is to treat September call-ups as garbage time. Last year disproved it: Trey Yesavage in Toronto and Connelly Early in Boston both debuted as September call-ups and both went on to start playoff games.
Two roster spots change how many relievers a manager can burn in a tied game, how quickly a struggling starter gets pulled, and which arms are available late on a road trip. In a wild card race decided by half a game — which is exactly where the National League sits right now — that is not marginal.
Already Up This Year
Several of the names that would have headlined this list arrived early. Kevin McGonigle has been among Detroit’s best players. Munetaka Murakami and Sam Antonacci have driven the White Sox to an unlikely division lead. Cleveland’s Parker Messick, Travis Bazzana and Chase DeLauter have all contributed to a club now holding the American League’s final wild card.
That is the modern pattern: the best prospects come up in June and July, not September.
The Eligibility Question
One deadline matters more than September 1. To be eligible for a postseason roster, a player must be in the organisation by 11:59 p.m. ET on August 31 — tonight. Anyone promoted tomorrow was already in the system, so eligibility is not the issue; being on the 40-man is.
Our September call-ups tracker logs the moves as they happen, and September call-ups explained covers the rules in full.
The Bottom Line
Rosters expand from 26 to 28 on September 1, with the pitcher cap rising to 14. Every addition must already be on the 40-man roster, which is the real filter. Josue De Paula, Gage Wood, Patrick Clohisy and Ethan Salas are among the most likely names — but contenders will spend most of these spots on relief arms, not bats.