Boston optioned Gasper to Triple-A Worcester on Sunday, Jen McCaffrey of The Athletic reports.
With both Trevor Story (abdomen) and Roman Anthony (finger) returning from the injured list, Gasper will wind up losing his spot on the 26-man active roster. The demotion comes even though Gasper had been running hot at the plate since being recalled from Triple-A on Aug. 16; over the last two weeks, he slashed .423/.595/1.115 with five home runs, three doubles, nine walks, 12 RBI and six runs in 11 games.