The Pirates have placed one of their better middle relievers on the 15-day injured list.
Colin Holderman is on the shelf with right wrist inflammation.
RHP pitcher Yerry De Los Santos has been called up from Triple-A Indianapolis.
De Los Santos is coming up to Pittsburgh for the second time this season. He was with the Bucs June 3 and 4 for games against the Cardinals.
Holderman is 0-1 with the Pirates over 26 games this season, posting a 4.01 ERA.
He has one save, over 24.2 inning pitched with 28 strike outs, seven walks, has given up three home runs and 11 earned runs.
De Los Santos appeared in one game this season pitching 0.2 of an inning with one strike out and one walk and no earned runs.
Last season, De Los Santos went 0-3 with a 4.91 ERA, 26 strikes outs, 11 walks and 14 earned runs.
The Pirates bullpen got roughed up on Wednesday evening with the Cubs overcoming a 5-1 deficit to beat Pittsburgh 10-6.