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Minor League Pitcher Grades: The Best Arms in the Minors Aug. 24-Sept. 6

Which recently-promoted players are starting to iron things out in AAA?

Keeping tabs on your current baseball dynasty pitching options is hard enough. Looking for the next diamond in the rough on the minor-league side is a job all by itself. Thanks to PLV, we can look at some arms of note and the pitching prospects doing the most in 2026.

With that in mind, let’s take a look at some Triple-A standouts from the season so far and check in on a Top 100 arm.

Check out the card tool at: https://milb-pitch-analysis-card.streamlit.app/ and other tools at: https://pitcherlist.com/pl-pro-tools-hub/

 

Top 100 Prospect Spotlight

 

Jamie Arnold, Athletics

 

2026 Stats: 24 GS | 118.1 IP | 3.42 ERA | 4.00 FIP | 25.1% K% | 9.9% BB% | 28.6% CSW%

Last Two Weeks: 5.0 IP | 0.00 ERA | 4 H | 0 ER | 2 BB | 5 K

 

In retrospect, the top five pitchers selected in the 2025 MLB Draft represented very different portions of the pitching prospect spectrum. From the high-ceiling prep prospect to a safe collegiate underslot pick, that group of five pitchers has really lived up to expectations so far. While Seattle Mariners prospect Kade Anderson needed just 18 Double-A starts before reaching MLB, the Athletics‘ 11th overall pick spent his entire professional debut season working through the hitter-friendly Texas League, taking his lumps in a rough May at Double-A Midland before settling into a genuinely dominant summer. Once those lumps fully healed, the Athletics finally bumped Arnold up to Triple-A Las Vegas, and his first start went about as well as possible.

His lone appearance in this window, a start against Sacramento, produced a solid line: 18 batters faced, five strikeouts, two walks, and a .296 wOBA allowed that essentially matched his .289 expected wOBA. His fastball, sitting at 93.6 MPH, led the way at 38.8% usage, with his plus sweeper mixed in nearly a third of the time. The sinker got hit a touch harder than you would like in this specific sample, with a .318 wOBA against, but that is one data point from one start at a brand-new level, not a trend. For my first look at Arnold in a while, this was not a super sharp start. There is only so much room to complain about five shutout innings with only four hits, but it felt like Arnold was the beneficiary of multiple balls put into play early, and overall, he was not in the zone (42% zone rate) but got a 36% chase rate. The fastball was the pitch he threw best for strikes, in the zone nearly 60% of the time and registering a 38% CSW%.

Arnold fell to Oakland at 11 despite entering the draft as MLB Pipeline’s No. 4 overall prospect, and evaluators drew immediate comparisons to Chris Sale for the shape of his delivery and the way his stuff plays beyond his listed velocity. The season-long numbers back up why. His 3.84 ERA at Midland undersells him significantly once you account for the environment. It is the best mark among all qualified Texas League starters not named Anderson. He capped his Double-A stint with a career-high nine strikeouts across 5.2 scoreless innings in early August, the performance that really made a late-season promotion to Triple-A seem inevitable.

I see the early Triple-A returns as exactly what you would hope for from a pitcher with a 60-grade fastball and a 65-grade slider making his first appearance above Double-A. The command markers held. The strikeout rate held. Arnold is the fifth pitcher from that loaded 2025 first round to reach Triple-A, and outside of Anderson’s rocket ride to the majors, nobody in that group has looked more like the version scouts promised on draft night.

 

Triple-A Standouts

 

Mason Molina, St. Louis Cardinals

 

2026 Stats: 25 GS | 113.0 IP | 3.82 ERA | 4.03 FIP | 28.7% K% | 10.3% BB% | 30.1% CSW%

Last Two Weeks: 15.0 IP | 0.00 ERA | 11 H | 0 ER | 3 BB | 23 K

 

The scouting report on St. Louis Cardinals prospect Mason Molina is refreshingly unglamorous. One evaluator told The Cardinal Nation flatly, “He is a generic fastball, slider guy. He does not have a lot of body projection.” That is not the kind of outlook that starts dynasty helium, or a Top 100 blurb. It is also increasingly hard to square with what the Arkansas alum has done lately on the mound.

Acquired from Texas in the trade that sent reliever Phil Maton to the Rangers last summer, Molina has climbed one level at a time without a hiccup. Last season was his first full one, split between the two organizations, but he ended up in High-A by the time it wrapped. The Cardinals started Molina off in Double-A Springfield in 2026, then promoted him off a 2.87 ERA and 82 strikeouts in 69.0 innings pitched. The stuff that gets him there is not loud. His fastball sits in the mid-90s only in the sense that it does not, hovering closer to average, and his breaking ball grades have never been anything special on a scouting sheet. What he has instead is a changeup that both righties and lefties simply cannot square up.

Across three starts in this window, Molina faced 57 batters and struck out 23 of them, a 40.4% rate against a walk rate of just 5.3%. His most recent outing, on Sept. 6, was the sharpest of the stretch: nine strikeouts against 20 batters faced, a .158 slugging percentage allowed, and a .143 wOBA that would rank among the better single-game marks any pitcher in the minors posted that week. The pitch data explains exactly why. His changeup, thrown a little over a fifth of the time in this window, allowed a wOBA of just .105, the best mark of any pitch in his four-pitch mix by a wide margin. His fastball backed it up at .201 wOBA against with a 31.3% swing-and-miss rate. That start specifically offers an interesting snapshot into Molina as a pitching prospect. The southpaw has had multiple nine-strikeout games this season, but he just throws so many pitches for strikes, and every offering in his mix registered a strike more often than not.

The pure stuff does not jump off the sheet, but it is hard to explain away what the former seventh-round pick has done as of late. He had a few blow-up performances around the trade deadline, but he has mostly been steady and reliable in limiting home runs, limiting walks, and getting five-plus strikeouts in a minor-league-quality start. Considering he is posting a 3.08 SIERA in 2026, Molina is a rising prospect in my books.

 

Garrett Baumann, Atlanta Braves

 

2026 Stats:  23 GS | 114.1 IP | 5.67 ERA | 5.04 FIP | 21.9 % K% | 9.6 % BB% | 24.7% CSW%

Last Two Weeks: 10.0 IP | 2.70 ERA | 13 H | 3 ER | 3 BB | 9 K

 

Atlanta Braves prospect Garrett Baumann has spent most of this season standing in the shadow of more decorated teammates. Players like Owen Murphy and Cam Caminiti have occupied the top of Atlanta’s pitching rankings for a while now, and Baumann, a 6-foot-8 fourth-round pick from 2023, does not get talked about nearly as often. That is starting to look like an oversight on a frame that is hard to miss.

The projectability has always been there. What has caught up to it in 2026 is the stuff. Baumann’s fastball now routinely touches the upper 90s, a jump from what scouts saw in previous seasons, and both his slider and splitter have made real strides alongside it. FanGraphs’ write-up on the Braves system captured the trajectory well, calling him a pitcher with “the look of an innings-eating No. 4 starter” who “might even have a tick of upside beyond that,” flagging him as a sleeper for the following year’s Top 100 list if the new velocity and sharper secondaries hold. Through this season, they have. He reached Triple-A Gwinnett by June, tracing the same organizational ladder as fellow Braves prospects JR Ritchie and Murphy before him.

Across two starts in this window, Baumann faced 48 batters, struck out nine, walked just three, and allowed a .333 wOBA that ran notably above his .276 expected mark. Baumann did not allow a single barreled ball across either start. His Sept. 4 outing saw more traffic than the one before it, eight hits and a .391 slugging percentage allowed, but even in that busier game, hitters were not squaring him up with authority.

The Braves demoted him for three starts last month back to Double-A, and since then, the pitch mix has shifted sharply. Baumann has trimmed his arsenal from six different offerings down to four, leaning more on one of his fastballs, a sinker or four-seamer, while doubling his slider usage in the process. That shift applies even more in platoon splits, where his usage really just falls to slider, four-seamer, and splitter against left-handed bats since his return. The righty has elite extension thanks to his build, and his perceived fastball velocity ranks near the top among his peers. I do not see anything yet that would cause me to disagree with Brendan Gawlowski’s outlook on Baumann, but the late-season shift gives me more hope than the season-level stats do on their own.

 

Jackson Wolf, Detroit Tigers

 

2026 Stats: 21 GS | 112.0 IP | 5.95 ERA | 5.11 FIP | 23.3% K% | 8.9% BB% | 28.3% CSW%

Last Two Weeks: 11.0 IP | 0.00 ERA | 3 H | 0 ER | 5 BB | 19 K

 

Dynasty value can come from some uncustomary places, but I did not anticipate going three seasons between the MLB debut and any other big league appearance like Detroit Tigers farmhand Jackson Wolf. The 27-year-old lefty was the San Diego Padres‘ No. 16 prospect back in 2023, the year he made his only major league start to date. That start came against Detroit, at Comerica Park, and Wolf won it, five innings and three runs allowed in a Padres rout. How things change in baseball. Wolf has now been vying to wear a Tigers uniform since joining the organization, by way of a trade that sent Casey Mize the other direction, with Wolf tagging along as the secondary piece behind the more heralded Kash Mayfield.

The résumé leading up to that trade was not pretty. Wolf spent 2026 grinding through a genuinely difficult season at Triple-A El Paso, sporting a 5-10 record and a 7.05 ERA across 89.1 innings. But underneath the ugliness, Wolf was still striking guys out at a decent clip. It just was not translating into results. That started to change following his Toledo debut, where he allowed only one hit in four scoreless innings on Aug. 9. The southpaw really dialed things up as the season came to a close.

Then came Aug. 28, and the box score caught fire. Wolf struck out 11 batters over five scoreless innings, matching a career high, working around four walks that limited his efficiency but never his effectiveness. Six days later, on Sept. 3, he was even better and considerably more efficient about it with six hitless innings and eight strikeouts against a single walk. The sweeper alone accounted for four of those strikeouts, and the opposition had no answer for it, whiffing on it five times. But it was the fastballs that led Wolf’s usage, with the sinker serving as his trusty pitch to land in the zone while he challenged batters with an interesting four-seamer up in the zone.

The dynasty reality is that while Wolf has a unique arm slot for a lefty starter, how well can a sub-90 mph fastball hold up in a rotation in 2026? Detroit is trying to figure that out, watching how he has cut back on the cutter and leaned more into the sweeper since joining the organization. Heading into his age-28 season, Wolf is not a pitcher I am going to slam the table for and say he is the must-target arm in proximity to the majors. But for now, the forgotten piece of the Casey Mize trade has given the Tigers a genuinely interesting piece to think about.