Barraclough was recalled from Triple-A Worcester on Monday.
Barraclough will assume the 26-man active roster spot of lefty Chris Murphy, who was optioned to Worcester in a corresponding move. The 33-year-old right-hander appeared in two games with the Red Sox earlier this month and recorded a win, a 2.70 ERA and a 1.20 WHIP while working 3.1 innings. He had slotted back into the Triple-A rotation after being optioned Aug. 13 and should provide the Red Sox with some extra length out of the bullpen upon rejoining the big club.