Winslow, whose NFL career has been slowed by injuries, was released Sunday from the Cleveland Clinic, where he spent three nights. Citing privacy laws, the Browns have not publicly discussed Winslow's illness. He was able to practice one day last week before he began to feel ill.
He was replaced in the starting lineup by Steve Heiden.
Winslow has 19 catches for 170 yards this season. Last season, he caught 82 passes for 1,106 yards.
The Browns also played their first Monday night game since 2003 without defensive end Shaun Smith. He broke his right hand on Sept. 21 at Baltimore but played with a cast two weeks ago at Cincinnati.