The Diamondbacks recalled Hollowell from Triple-A Reno on Tuesday.
The right-hander was optioned to Reno after being claimed off waivers from the Rockies in mid-June, and he'll now receive his first look with the Diamondbacks. Hollowell made 26 appearances in the big leagues last year for Colorado and had a 5.88 ERA, 1.46 WHIP and 32:18 K:BB over 33.2 innings.