Romero was recalled from Triple-A Memphis on Sunday.
Romero will take the place of Drew VerHagen, who landed on the 15-day injured list with a hip impingement. Since his last stint in the majors, Romero has pitched to a 3.52 ERA, 1.57 WHIP and 22:9 K:BB over 15.1 innings as a reliever for Memphis. He'll likely take on a low-leverage relief role while on the big-league roster.