Bolanos allowed a run on two hits and two walks while striking out four over 3.1 innings in Saturday's 11-2 loss to Oakland.
The right-hander was called on for a multi-inning appearance after starter Jackson Kowar was pulled with one out in the second inning. Bolanos fared better in his outing, but it didn't change the result of the game. The 24-year-old has a 1.42 ERA, 0.95 WHIP and 10:2 K:BB across 6.1 innings this year. He worked as a starter with Triple-A Omaha this year, and Bolanos could tabbed for a spot in the rotation given Kowar's poor performance through two major-league starts.