Pirates Strengthen Bullpen Depth with Isaac Mattson Signing

The Pittsburgh Pirates have bolstered their pitching roster by signing right-hander Isaac Mattson to a minor league deal, as confirmed by MLB.com's transaction tracker and Mattson's own announcement on Instagram. Mattson, who has been assigned to Triple-A Indianapolis, is expected to receive an invitation to big league spring training.


Mattson, 29, also signed a minor league contract with the Pirates for the 2024 season. He was called up in September, pitching 5 1/3 innings over three appearances and allowing three earned runs. His brief major league experience includes four games with the Orioles in 2021, resulting in a 5.59 ERA over seven games. He was outrighted off the roster at the start of the offseason.


While this limited major league sample size doesn't provide much to draw conclusions from, the Pirates observed Mattson closely during the 2024 season in Triple-A. Over 60 innings in 29 appearances, he posted a 3.15 ERA, with a 29.8% strikeout rate and a high 12.9% walk rate. His performance in the upper minors has generally been consistent, with a 4.10 ERA, 27.9% strikeout rate, and 14.5% walk rate over 138 1/3 innings in the past four years.


​With this signing, the Pirates aim to strengthen their bullpen depth, hoping that Mattson can translate his minor league success to the major leagues in the upcoming season. As spring training approaches, all eyes will be on Mattson to see if he can secure a spot on the big league roster and make a significant impact.