Romero (appendectomy) will begin a rehab assignment Tuesday at High-A Wisconsin.
The 29-year-old southpaw will be making his organizational debut, after the Cardinals placed him on the injured list coming out of the All-Star break following his emergency appendectomy before trading him to the Brewers on Aug. 3. Because he's been out for more than a month, the Brewers will likely want Romero to make multiple appearances in the minors before clearing him to join the big-league bullpen. He could be a candidate for activation when the roster expands to 28 men Sept. 1.