The Red Sox needed to make a roster move with designatad hitter David Ortiz set to be activated for Friday night's game against the Royals.
The 22-year-old Bradley was in an 0-for-20 slump at the time of his demotion.
He was the story of Spring Training for Boston, hitting .419 with two homers and 10 RBIs while playing solid outfield defense.
The Red Sox promoted Bradley to the Majors earlier than planned because of the opportunity created by Ortiz's injury.
On Opening Day at Yankee Stadium, Bradley made a spectacular lunging catch to take an extra-base hit away from Robinson Cano.
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.