Pirates place reliever Colin Holderman on 15-day IL, recall Isaac Mattson from Triple-A

The Pittsburgh Pirates placed right-handed reliever Colin Holderman on the 15-day injured list with right thumb inflammation and pain, manager Don Kelly said Tuesday afternoon at PNC Park.

To add bullpen depth, righty Isaac Mattson was called up from Triple-A Indianapolis Tuesday before the Pirates hosted the Cincinnati Reds.

Infielder Nick Gonzales was transferred from the 10-day to 60-day injured list, creating a 40-man roster spot for Mattson.

Holderman, 29, has experienced significant struggles this season, going 0-1 with a 9.00 ERA over 14 games and 15 innings.

In Monday’s 7-1 loss to the Reds, he allowed three runs on three hits in 1 1/3 innings.

Holderman has walked and struck out 11 this year, has a 2.07 WHIP, and opposing batters are hitting .345 against him. He has allowed earned runs in nine of his 14 appearances.

In April, he went on the injured list because of a right knee sprain.

This is the 29-year-old Mattson’s first recall to the big leagues this season.

Over 16 relief appearances with Indianapolis, he has gone 2-0 with a 2.50 ERA, striking out 22 with five walks in 18 innings.

He throws three pitches, per Statcast: a four-seam fastball, changeup and slider.

Mattson, an Erie native who played three seasons collegiately at Pitt (2015-17) before being selected in the 19th round of the 2017 MLB Draft by the Los Angeles Angels, made three appearances with the Pirates last September.

Before that, he had last appeared in an MLB contest in 2021 with the Baltimore Orioles.

He has been in the Pirates organization since December 2023, when he was inked to a minor-league contract.

The Angels traded him to Baltimore in 2019, and in 2023, he joined the Minnesota Twins organization for a season before signing with the Pirates in the offseason.

In 2024 with Indianapolis, Mattson was named the team’s pitcher of the year after going 5-1 with a 3.15 ERA over 60 innings and 29 games, striking out 76.