Allard was optioned to Triple-A Round Rock on Wednesday, Levi Weaver of The Athletic reports.
The 23-year-old appeared in 11 games for the Rangers last season and posted a 7.75 ERA, 1.51 WHIP and 32:20 K:BB over 33.2 innings and won't open 2021 on the big-league roster. Allard was mentioned this spring as a candidate to be part of a piggyback tandem rather than serve as a traditional starter, though he figures to be part of the rotation at Triple-A.