The Giants placed Winn on the 15-day injured list Saturday with right elbow inflammation, Shayna Rubin of the San Francisco Chronicle reports.
Winn returns to the IL for the second time this season on account of an arm issue. He likely suffered the elbow injury during his start in the Giants' 6-5 loss to the Cardinals on Thursday, when he allowed five earned runs in just 2.2 innings. The Giants haven't yet named a replacement in the rotation for Winn, who holds a 3-8 record and 7.16 ERA through his 12 starts.