The Athletics announce their Arizona Fall League roster: An Overview

The Arizona Fall League rosters have been released this week with a lot of intriguing prospects on each team. There are six teams full of prospects from Major League teams that will play starting October 6th. I’ll be writing an article and making Twitter posts about each team’s roster. This will cover the prospects from the Athletics who are on the Mesa Solar Sox this fall. The team will consist of players from the Chicago Cubs, Miami Marlins, Tampa Bays Rays, and New York Yankees as well.

Athletics:

Mark Adamiak RHP: The 15th round pick in 2022 has been slowly climbing the past couple years. After spending most of the season in High-A Adamiak was recently promoted to AA after putting up some solid stats out of the bullpen with a 2.94 ERA and 3.45 FIP. Adamiak hasn’t had any public pitching data since his days at Arkansas where he had a FB that sat 95 mph with a slider with above average slider and a solid changeup. From the stats I do have available it seems turned into more of a command pitcher with less overpowering stuff. He has a walk rate of only 6.4% this year and a strikeout rate of 20.2%. After some shaky years at almost every stop, 2025 has been easily his best year. The A’s will look for him to continue that into AA and eventually Arizona. 

Corey Avant RHP: After being a reliever his entire college career at Division II Wingate University Avant continued to mostly be a reliever for the first two seasons in the A’s organization but has mostly transitioned to a starter this season and has been successful enough to earn a promotion to AA. After a 2024 season of being a multiple inning reliever he had a 7.39 ERA but this season at High-A he had a 3.65 ERA with a 3.34 FIP. He doesn’t have overpowering stuff but is able to limit hard contact and get outs. His first two outings in AA though have not been pretty, his first being from the bullpen where he allowed seven hits and five runs through two innings and the second a start where he allowed three hits and a walk for four runs through 2.2 innings. He isn’t Rule 5 eligible until after the 2027 season so the A’s don’t have to make a decision on him very soon. Hopefully he can get back to his High-A form.

Nathan Dettmer RHP: The former 5th round pick out of Texas A&M didn’t pitch after August last year after being diagnosed with bone spurs in his pitching elbow but was cleared to play for the 2025 season. In 109.1 innings between Low-A and High-A he has a 5.93 ERA and 4.77 FIP. He hasn’t been able to overpowered hitter with a 17.4% strikeout rate and with an 8.9% walk rate he’s had okay command but in his six starts in High-A he only has 19.8% CSW% with only a 6.9% swinging strike rate. With missing so much time last year and having a disappointing season it’s important for him to finish strong. I’m excited to get some Statcast numbers on him this fall.

Will Johnston LHP: Another Texas A&M pitcher drafted by the A’s in 2023 Johnston has moved quicker through the organization than Detmer entering AAA this season. He’s a lefty with a deceptive delivery that hides the ball for a long time. This helps him hide his below average stuff. He has a fastball that sits in the low 90s with a split changeup that at times has looked like a great strikeout pitch but has been inconsistent in its movement profile. He also has a slider that’s still a work in progress and a sinker he started throwing this season. After being mostly a starter for the start of his career and college Johnston has transitioned to a bullpen role this season going from pitching as a regular starter to throwing two innings or less since the start of May. With his deceptive delivery he’s able to get a good amount of strikeouts at 32.9% in AA but his command which was a problem in college has gotten significantly worse this season going from 9.7% in 2024 to 13% this season. He’s looking like a potential left handed reliever in the back of the A’s bullpen potentially as soon as next year. 

Blaze Pontes RHP: The former 16th round pick out of Hawaii has had a solid season in High-A. In his first two pro-ball seasons Pontes was a multiple inning reliever but transitioned into a one inning guy this season and that’s paid off. He has a 1.79 ERA but with his low strikeout rate his FIP is up to 3.39. He’s mostly a command pitcher who hasn’t shown the stuff to miss many bats but limits hard contact and hasn’t given up a homer in all of 2025. Not a super impactful arm and has lower potential than guys with massive stuff but could find a good niche and role with his skillset. 

Joshua Kuroda-Grauer SS: The former Rutgers 3rd round pick got all the way up to AAA in the same year he was drafted last season. This year in his first year in pro ball he started at High-A and has looked okay. After playing his first eighty games in High-A he slashed .293/.353/.362 with a below average 95 wRC+. He then was promoted to AA and has played forty one games so far and put up better numbers with a .301/.372/.393 slash and a 117 wRC+. He’s a contact centered bat who only swings 43% of the time but makes some of the most contact in the minors at a 87.4% rate this season. He doesn’t chase often and even when he does he makes good contact out of the zone. He could climb through the minors with his bat quickly just like current A’s shortstop Jacob Wilson did. He likely won’t be taking Wilson’s spot at short, though with only an average arm he’ll likely be moved to second base as he gets closer to the majors.

Tommy White 3B: The first pick of the second round in last year's draft White was a major piece in LSU’s championship run in 2023. He’s a big power hitter with some of the best bat speed in the 2024 draft. He also has very solid contact skills at an 81.9% contact rate this season. He doesn’t whiff often especially in the zone and swings 55.1% of the time which causes him to walk at a below average rate. His biggest problem is his chase issues. He makes so much contact that he doesn’t pick the best pitches to swing at and tends to make weak contact on pitches out of the zone. He also hasn’t shown his power since being promoted to AA or in the months before that in High-A. In the month of May after coming off the injured list in only 36 plate appearances White hit .412/.444./.912 with five home runs and two doubles showing the potential he had as a hitter but since then he’s significantly regressed especially from the power standpoint only hitting five home runs in the next 250 plate appearances. This shows the volatility that his bat can bring. He’s putting up better overall numbers since being promoted and making better contact but he’s also swinging more and walking less. He does have the ability to stick at third with a solid glove and some unexpected athletic ability but could end up at first base as well. Hopefully he can find his power and breakout this fall. 

Ryan Lasko CF: Another player the A’s took out of Rutgers, Lasko was drafted in the 2nd round of the 2023 draft and has had a rough time adjusting to pro-ball pitching. Out of college he looked like he had the ability to hit for power and decent contact ability but both have fallen off since getting into the A’s organization. This year he’s battled a few injuries at the start of the year and after a decent 72 games in High-A he has been promoted to AAA where he’s struggled even more to hit early. In High-A he slashed .241/.359/.339 with a 94 wRC+. He walks a decent amount at 13% this season but also strikeouts out at 23.2% of the time. He doesn’t chase a lot but whiffs too much in the zone with a Z contact of only 70.1%. His calling card is his elite defense in center field which could get him to the big leagues as a bench outfielder or a defense first speed type if he can steal more bases.

Thank you for reading for shorter breakdowns check out my Twitter @drew-durstock. Each day I'll release a new team's prospect breakdown.