Orioles manager Buck Showalter said Sunday the pair will play at least three games with Bowie.
Hardy hasn't played this season because of a strained left shoulder. His status will be evaluated after the three-game stint.
Flaherty is out with a strained right groin and could return by the weekend.
Matt Wieters is catching at extended spring training, but there is no date yet for when he will start a rehab assignment as he comes back from elbow ligament replacement surgery.