The Brewers optioned Milner to Triple-A Nashville on Tuesday, Tom Haudricourt of the Milwaukee Journal Sentinel reports.
The lefty has struggled since joining the Brewers' bullpen, posting a 5.91 ERA in 10.2 innings. Milner's 14:1 K:BB has certainly impressed, though, so it wouldn't be shocking to see him back with the big-league club at some point this season.