(CBS) The Cubs on Friday recalled right-handed reliever Felix Pena from Triple-A Iowa and optioned right-handed reliever Justin Grimm down.

The move was made with several factors in mind. With Cubs starters struggling to go deep in games for weeks, the bullpen has been taxed, and Pena serves as a fresh arm. Grimm has also been struggling, as he has a 7.30 ERA in 12 1/3 innings this season. Grimm didn’t allow a run in a 5-4 win against the Phillies on Thursday, but he allowed two hits and two walks in 2/3 innings.

Pena has a 1.86 ERA at Triple-A this season, striking out 11 in 9 2/3 innings. He had a 4.00 ERA in nine innings for the Cubs in 2016.