Manager Alex Cora said Bello (groin) will be activated off the 15-day injured list to start Wednesday against the Blue Jays, Alex Speier of The Boston Globe reports.
The 23-year-old landed on the shelf Aug. 4 with a strained left groin, and he'll rejoin Boston's rotation after a two-start rehab stint in the minors. Bello covered 4.1 frames in his last rehab outing and has an 8.47 ERA across five big-league appearances this season. The rookie could be used in conjunction with veteran lefty Rich Hill.