September roster expansion isn’t what it used to be. In fact, teams don’t always even wait until Sept. 1 before making their call-ups. (Old man voice) Back in my day, they called up a hundred guys and crammed them all into the dugout. Prospects would have to sit on the veterans’ laps. And we liked it! Anyway, with roster limits only increased to 28 instead of 40, we now get just a couple of prospects debuting or resurfacing in September each year.MLB September callups to noteKeith LawSince Aug. 28, we’ve seen two prospects from my midseason top 70 prospect ranking make their debuts, as well as several other prospects of note. Here are some updated thoughts on each of them.Ethan Salas, C, San Diego Padres (No. 11 on the midseason top 70)Salas is the top-ranked prospect to earn a big-league promotion so far around the roster-expansion date. His debut is the culmination of a breakout year for the 20-year-old, who played just 10 games in 2025 due to a lower back injury.Salas spent most of this year in Double A, hitting a respectable .286/.361/.417 while still being young for the level. Since moving up to the hitters’ haven of Triple-A El Paso, he’s hit .326/.410/.539. It’s more hit than power right now; his underlying power data in Triple A is slightly above-average, with a boost from El Paso’s park and a five-game series in Reno, located on the surface of Europa. He’s a strong defensive catcher with a plus arm.While the promotion seems aggressive, the Padres have been giving Freddy Fermin, one of the worst hitters in baseball this year with a 64 wRC+, regular playing time behind the plate, so it wouldn’t be hard for Salas to produce more than that, especially with the benefit of being left-handed.Walker Jenkins, OF, Minnesota Twins (No. 19 on the midseason top 70)Jenkins came up over the weekend, debuting on Friday, and hit his first home run on Monday night. He only played 69 games in Triple A this year due to some not-nice injuries, but when he played, he raked, hitting .308/.407/.532 with a 90th percentile EV of 106.4 mph and a hard-hit rate of 44.3 percent.Walker Jenkins smiles after hitting his first MLB home run. (Matt Krohn / Getty Images)He’s using the whole field well and has shown excellent pitch recognition across the board. I do think he’s going to get to more power in time, when he learns when to try to pull the ball, and I think he’ll also end up a plus defender in right field. He has to stay healthy, however, as his pro career has been marked as much by injuries as by production.Lazaro Montes, OF, Seattle MarinersMontes was on my top 100 ranking over the winter but did not make the midseason top 70 because the long-standing worries about his pitch selection have started to overwhelm the rest of his game.Montes hits the ball about as hard as anyone in the minors, with a hard-hit rate in Triple A of 54.6 percent, a 90th percentile EV of 109.0 mph and a max of 116.3. He hit 28 percent of his balls in play at 104 mph or harder, which is higher than Jacob Wilson’s hard-hit rate (greater than 95 mph) in the majors this year.But with great power often comes great swing and miss. In Double A this year, Montes whiffed on 40 percent of his swings, which dipped slightly to 38 percent in Triple A, with the benefit of road series at Las Vegas (twice) and Reno. He chased pitches out of the zone 27 percent of the time in Double A and 32 percent of the time in Triple A. On pitches well outside of the zone, he chased 16 percent in Double A and 23 percent in Triple A. That last one is the most worrisome — he’s swinging way too often at non-competitive pitches, and of course, he’s not hitting them, either.Laying off of those pitches has allowed hitters such as Kyle Schwarber and Munetaka Murakami to be valuable despite enormous strikeout rates, because they take their walks and do a ton of damage when they do swing. That’s Montes’ upside, and if he makes that adjustment, he’s going to hit 40 homers in a season at some point.Luis De León, LHP, Baltimore OriolesDe León has mostly worked as a starter this year but moved to a short relief role two weeks ago, which I assumed was because he wasn’t getting righties out but may instead have been in preparation for a call-up.He’s a sinker/slider guy whose fastball is 94-96 mph. He has a fringy slider that plays up a little because he throws it hard, killing lefties this year but allowing a .280/.375/.456 line to righties. He throws the slider more to righties than he throws his changeup and splitter, both of which are pretty good.I think the changeup’s a 55 (on the 20-80 scouting scale) — probably his best overall pitch — and would be much more effective against hitters on the other side of the plate, while right-handers have feasted on the slider all year. So while he’s probably going to pitch in relief for now, I want to see what he looks like as a starter if he stops throwing breaking stuff directly at right-handed hitters’ bats.Leo Bernal, C, St. Louis CardinalsThe Cardinals’ catching pipeline just keeps on delivering, with Bernal following in the footsteps of fellow Panamanian backstop Iván Herrera, and with star prospect Rainiel Rodriguez (from the Dominican Republic) storming up behind them.Bernal improved across the board this year at the plate, continuing to get stronger and making harder contact, to the point now that you can project 15-20 homers a year from him if he’s an everyday catcher. His bat is his strong point, while his defense is adequate enough to keep him at catcher, given how well he hits, although the Cardinals just had this with Herrera and decided to make him primarily a DH and occasional catcher.Yohandy Morales, 1B/3B, Washington NationalsThe Nationals’ second-round pick in 2023 (40th overall), Morales repeated Triple A this year and improved his production across the board, including a career-high 25 homers, but even a reduced strikeout rate hides the fact that he’s overmatched by decent stuff. On fastballs 95+ this year, he’s whiffed 43 percent of the time he’s swung, and on anything that’s not a fastball, he’s whiffed 35 percent of the time.He might do fine in a small sample but the lack of pitch recognition and insufficient bat speed are going to be real problems.Ricky Tiedemann, LHP, Toronto Blue JaysRanked as the Blue Jays’ top prospect heading into the 2024 season, Tiedemann is mostly a two-pitch reliever at this point, with a mid-90s four-seamer and a big mid-80s sweeper that gets a ton of horizontal movement thanks to his low three-quarters arm slot.He missed most of 2024 and all of 2025 due to injuries, including an elbow injury that required Tommy John surgery. He’s only thrown 13 2/3 innings this year in total, including his 1 2/3 inning major-league debut two weeks ago (he was sent down afterwards and recalled again on Sept. 1). I imagine he’ll be a short-relief option for the Jays when a couple of lefties are due up.Tanner McDougal, RHP, Chicago White SoxMcDougal also debuted in mid-August, making one appearance, facing five batters and walking three of them while hitting another. It could have gone better.He came into the season as the White Sox’ No. 6 prospect, but suffered a flexor strain in his sixth outing and missed a little over two months, returning as a reliever and really struggling with his control. He sits 97-98 with a hammer curveball and hard slider, barely using a changeup, so lefties have smoked him this year, including a .408 OBP. I worry he’s not over the forearm injury.