Hoping to help their beleaguered bullpen, the Cardinals acquired right-hander Blaine Boyer from the Braves in exchange for Triple-A outfielder Brian Barton on Monday.

Boyer is expected to be at Busch Stadium and available to pitch for Tuesday’s game against the Mets. The Cardinals will demote a position player to make room for him. That will likely be David Freese, though general manager John Mozeliak did not announce the corresponding move in a conference call on Monday afternoon.

Boyer, 27, got off to a rough start with Atlanta in 2009 and was designated for assignment. In three appearances, he allowed six runs in 1 1/3 innings.