Pirates place Colin Holderman on IL, recall relief pitcher Isaac Mattson

Erie native RHP Isaac Mattson returns to the Pirates, Nick Gonzales moves to the 60-day injured list

The Pittsburgh Pirates are pulling the plug on Colin Holderman in the bullpen for the next few weeks.

On Tuesday afternoon, the Pirates announced they placed the right-handed reliever on the 15-day injured list. Donny Kelly told the media that Holderman is dealing with thumb inflammation. Right-handed relief pitcher Isaac Mattson will take Holderman’s place in the bullpen.

Holderman, 29, has been a big disappointment for the Pirates’ bullpen since allowing a three-run home run to Joc Peterson on August 4, one of the main at-bats that sunk the Pirates’ season last year.

In 2025, Holderman owns a 9.00 ERA and -0.8 WAR. He’s allowed 15 earned runs in 15 innings and owns a 2.07 WHIP. Holderman has walked as many batters as he’s struck out (11) and has allowed three home runs in 14 games. He allowed three runs in 1.1 innings Monday night ad the Reds scored five runs in the last two innings to defeat the Buccos, 7-1 at PNC Park.

Despite his struggles last season, he still compiled a solid 3.16 ERA through 51.1 innings and was the Pirates’ best reliever for the first three months through April (1.35 ERA), May (0.77), and June (1.59) before a 5.79 mark in July and 18.00 in August.

Mattson joins the Pirates for the second time in as many years after pitching in three games during the 2024 season. Following 16 games with Triple-A Indianapolis, Mattson earned a 2.50 ERA, 0.94 WHIP, and 22 strikeouts in 18 innings. The 29-year-old righty from Erie pitched at Pitt from 2015-17 before being drafted by the LA Angels in the 19th round of the 2017 MLB Draft.

To make room on the 40-man roster for Mattson, the Pirates transferred second baseman Nick Gonzales from the 10- to 60-day IL. Gonzales has not played since Opening Day (March 27) and is still working his way back from an ankle injury. The Pirates placed Gonzales on the injured list 53 days ago (March 28) and he is currently rehabbing at Triple-A. Gonzales is still on track to join the Pirates in the next few weeks.

The Pirates host the Reds Tuesday night at PNC Park, looking to win their first game against Cincinnati in four tries. The Pirates have been outscored 21-6 by the Reds in their first four matchups this year.