A’s Prospect Mason Barnett Has an Atypical Arm Angle and an Old-School Approach

Mason Barnett doesn’t profile as a front-of-the-rotation starter, but he does project to provide solid innings for a major league staff. A 25-year-old right-hander who made his MLB debut with the Athletics at the end of August, Barnett is currently viewed by Eric Longenhagen as “a big league starter who has demonstrated durability [and] is a no. 4/5 on a good team.” Our lead prospect evaluator anticipates assigning him a 45 FV when our 2026 A’s list is published in the not-too-distant future.
The Kennesaw, Georgia native was originally in the Kansas City system. Drafted 87th overall by the Royals in 2022 out of Auburn University, Barnett was subsequently traded to his current club in the 2024 deadline deal that sent Lucas Erceg to America’s Heartland. With his time down on the farm now mostly complete, Barnett will head into the forthcoming campaign having logged a 6.85 ERA and a 4.88 FIP over five starts comprising 22 1/3 innings in his initial major league opportunity.
Longenhagen has assigned a 40/45 on the righty’s command, and it was that aspect of his game that Scott Emerson emphasized when I asked him about Barnett toward the tail end of last season.
“Barnett, interesting guy,” said the longtime Athletics pitching coach. “Very good competitor. Throws strikes with his fastball, which has some cut-ride. He’s got a good developing changeup. He spins the ball really well and has both the sweeper and the curveball. For me, a lot of it with Barnett is his being able to execute his pitches inside the strike zone when he needs to, and then being able to make them chase outside of the strike zone when he’s ahead in the count. He’s one of our guys who needs to learn to command the ball better.”
The numbers back that up. Barnett had a 10.8% walk rate (as well as a 17.3% strikeout rate) in his big league cameo, while in Triple-A those numbers were 11.9% and 22.8%. But, while concerning, it’s not as though he can’t throw strikes or miss bats. In 2024, he punched out Double-A batters at a 28.5% clip, and walked them at a more-acceptable (albeit still not great) 8.7% over 133 innings of work. Like Longenhagen and Emerson, Barnett also recognizes the need to improve his strike-throwing. Read the rest of this entry »







