The Brewers acquired Stallings from the Orioles on Saturday in exchange for right-handers Thyago Vieira and Aneuris Rodriguez.
Stallings has spent all season with the Orioles' Triple-A affiliate in Norfolk, posting a 5.67 ERA and 1.63 WHIP across 27 innings. He hasn't found much success at any minor-league level he's pitched at and doesn't figure to be in line for a call to the majors anytime soon, but he'll give the Brewers organizational depth at Triple-A Nashville.