The Brewers recalled Ashby from Triple-A Nashville on Sunday.
The left-hander has started in 14 of his 25 appearances for Nashville this season, and he's recently been operating out of the bullpen. Ashby has delivered six straight scoreless appearances at Triple-A and has a 14:1 K:BB during that stretch. He'll step into a relief role for the Brewers, taking the roster spot of Nick Mears (forearm).