Lamet's contract was selected from Triple-A Worcester on Monday.
He signed a minor-league contract with the Red Sox on June 28 and has logged a 3.72 ERA, 1.19 WHIP and 16 strikeouts in 19.1 innings over his last five appearances. Lamet went five innings deep in his two most recent games, so he will be capable of logging multiple innings per appearance, presumably out of the bullpen.