The Athletics acquired Blewett from the Cardinals on Sunday in exchange for cash considerations Martin Gallegos of MLB.com reports.
After being designated for assignment by St. Louis a few days earlier, Blewett will recapture a 40-man roster spot as he moves on to Sacramento. The right-hander has produced a 5.18 ERA and 1.68 WHIP with 63 strikeouts over 48.2 innings in 37 appearances with Triple-A Memphis this season and tossed two scoreless innings in his lone outing at the big-league level. Blewett doesn't have any minor-league options remaining, so he'll join the Athletics bullpen right away.