Allen was optioned to Triple-A Las Vegas on Sunday.
Allen made a strong case for an Opening Day roster spot this spring by going 6-for-12 with a home run, two triples, three runs, three walks and three strikeouts across seven Cactus League games. While he'll head to Las Vegas to begin the regular season, the 23-year-old is a strong candidate to make his major-league debut for the rebuilding Athletics if he performs well in the minors early in the year.