TORONTO -- Red Sox outfielder Allen Craig has been optioned to Triple-A Pawtucket, a baseball source told MLB.com's Ian Browne on Saturday night.

According to the source, the 30-year-old Craig was heading for the PawSox following an 0-for-4 performance against the Blue Jays in Saturday's 7-1 loss. The Red Sox have not confirmed the move.

Craig's service time means he must accept the assignment.

PawSox outfielder Jackie Bradley Jr. was a late scratch ahead of Saturday's contest against Columbus.

Bradley was slated to lead off and play center field, but the club swapped him out for Quintin Berry a few hours later, possibly indicating that Bradley is on his way to join the Red Sox

The 25-year-old is hitting .343 (34-for-99) with one homer in 24 games for Pawtucket. He's yet to appear in a game with the Red Sox this year.

Craig has struggled in 2015. In 23 games, he's hitting .146 (7-for-48) with one homer.

Originally acquired from the Cardinals in a trade for John Lackey, Craig has been unable to recapture his 2013 form, when he hit .315 with 13 home runs and a career-high 97 RBIs.

Red Sox manager John Farrell suggested following his team's seventh loss in its past eight games that a roster shakeup could be on the way.

Since going 3-0-1 in their first four series, the Red Sox are 1-5-0 in their past six.