The Rangers optioned Collyer to Triple-A Round Rock on Tuesday.
The right-hander threw 35 pitches in three innings across Sunday's and Monday's contests, so he'll be the odd man out of the bullpen with Chris Martin (biceps) coming off the injured list. Collyer has been an effective relief option for Texas this year with a 2.84 ERA, 1.11 WHIP and 10:8 K:BB across 12.2 innings, so it should only be a matter of time before he's back in the big-league bullpen.