Bolanos was recalled from Triple-A Omaha on Thursday.
Bolanos served as the 27th man during a doubleheader in mid-May, but he failed to make an appearance in the twin bill. He'll now return to the major-league club after he posted a 3.31 ERA and 1.30 WHIP in 16.1 innings during four starts with Triple-A Omaha this year. The right-hander will likely serve as a low-leverage reliever but could be available as a spot starter if needed.