The Astros designated Alexander for assignment Thursday.
Alexander will end up as the roster casualty necessary to make room for Jose Barrosa, who was selected to the active roster Thursday. Alexander has struggled mightily during his time in the majors, logging a 9.33 ERA and 1.58 WHIP in 18.1 innings, and he hasn't been very effective at Triple-A either (5.26 ERA, 1.49 WHIP, 87.1 IP).