Athletics pitching prospect Mason Barnett will make his major-league debut on Saturday and start against the division-rival Texas Rangers, according to manager Mark Kotsay. Barnett, the team's 10th-ranked prospect per MLB Pipeline, will get the call to the big leagues for the first time after going 6-2 with a 6.13 ERA, 1.59 WHIP and 124:65 K:BB in 119 innings over 25 appearances (23 starts) for Triple-A Las Vegas in the hitter-friendly Pacific Coast League. With lefty Jacob Lopez (elbow) on the injured list, the 24-year-old right-hander will be auditioning for a starting rotation spot for the A's for the final month of the 2025 campaign. The Rangers are a friendly matchup for opposing starters, but Barnett will only be a streaming option for the desperate in DFS and deep fantasy leagues. The 6-foot, 218-pounder mostly relies on a mid-to-high-90s fastball, a sweeperish slider, a curveball and a changeup.

The Athletics promoted right-handed pitching prospect Mason Barnett after placing left-handed pitcher Jacob Lopez on the injured list. Barnett is the Athletics' number 11 overall prospect according to MLB.com, and his role is still to be determined. His numbers are poor at Triple-A Las Vegas this year, owning a 6.13 ERA, 1.60 WHIP, and a 10.8% K-BB% in 119 innings. The right-hander is striking out fewer hitters and walking more than he has at any stop in the minors this season. He's coughed up six runs in each of his last two outings in what has been a tough month of August. Given the role uncertainty and unfriendly home ballpark, Barnett doesn't profile to be relevant for fantasy purposes except in the deepest of leagues.