Otto was recalled from Triple-A Round Rock to start Friday against the Athletics.
Otto was already labeled Texas' probable starter for Friday's contest, and he's now officially joined the big-league roster. The 26-year-old made his major-league debut last season and had a 9.26 ERA across 23.1 innings, though he was off to a strong start at Triple-A this year with a 9:1 K:BB over seven scoreless innings.