Brasier was recalled from Triple-A Pawtucket ahead of Saturday's contest against the Orioles.
The promotion comes after Chris Sale (elbow) was placed on the 10-day injured list, retroactive to Aug. 14. Brasier was 2-0 with a 0.96 ERA and 13 strikeouts across 9.1 innings in the minors since he was sent down July 16. The right-hander will return to a Red Sox bullpen that has struggled in his absence.