Alexy was optioned to Triple-A Round Rock on Wednesday.
Alexy was called up at the end of August, and he gave up two runs on five hits and two walks while striking out two in 2.1 innings in his lone appearance during his stint with the big-league club. The right-hander will head back to the minors after Cole Ragans (calf) was reinstated from the 15-day injured list Wednesday.