Cousins was placed on the 10-day injured list Sunday with a right elbow effusion, Curt Hogg of the Milwaukee Journal Sentinel reports.
Cousins pitched a scoreless inning Saturday against the Cubs and allowed a hit with three strikeouts and two walks, and he'll now be sidelined by an elbow issue. It's unclear how long the right-hander will be sidelined, though he'll be eligible to be activated from the injured list May 11.