The Rangers recalled Collyer from Triple-A Round Rock on Tuesday.
Collyer will give the Rangers' bullpen a fresh arm after the club used five pitchers in Monday's win over the Guardians. The 25-year-old was unscored upon in his first 11 outings earlier this season but was sent to Round Rock after posting an 8.59 ERA and 7:10 K:BB over his last seven outings.