(CBS) The Cubs have called up left-handed reliever Zac Rosscup from Triple-A Iowa and optioned right-hander Dylan Floro down in a corresponding move.

The 28-year-old Rosscup has a 3.45 ERA and 1.02 WHIP in 15 2/3 innings at Iowa this season. He last pitched in the big leagues in 2015, with a 4.39 ERA in 33 appearances for the Cubs.

After recently being called up, Floro made a poor impression Sunday, allowing five runs, all earned, in two innings of work in the Cubs’ 13-6 win against the Brewers.

A corresponding move for the 40-man roster hasn’t been announced by the Cubs. One is needed because Rosscup wasn’t on the 40-man roster previously.