(CBS) The Cubs’ rotating cast of characters has continued in their bullpen.

Chicago has called right-handed reliever Felix Pena up from Triple-A Iowa and sent left-handed reliever Zac Rosscup down. Rosscup has just been promoted Monday, and he recorded 2/3 scoreless innings in a 6-4 loss to the Giants.

Pena has a 3.60 ERA in five innings of work for the Cubs this season. He has a 5.40 ERA in 13 1/3 innings at Triple-A.