Updated

Red Sox outfielder Jacoby Ellsbury has left the team and headed back to Boston for further evaluation of a right foot injury which has kept him off the field the last several days.

The Boston Herald reported that Ellsbury underwent an MRI on Saturday morning, which revealed inflammation near the navicular bone in his right foot.

Ellsbury sustained the original injury to the area when fouling a pitch off the foot last week, and then aggravated the issue during the 10th inning of Thursday's series-opening 9-8 victory over the Yankees.

The paper stated that the 29-year-old's affected foot has been placed in a walking boot and will be evaluated by team orthopedist Dr. Peter Asnis and foot specialist Dr. George Theodore. Ellsbury is expected to seek a second opinion from Dr. Thomas Clanton at the Steadman Clinic in Denver, according to the Herald.

While Red Sox general manager Ben Cherington expressed optimism that Ellsbury could return before long, manager John Farrell recognizes it may not be a day- to-day issue. An injury to the navicular bone can have serious consequences, such as former outfielder Cody Ross being out of commission for a month and second baseman Dustin Pedroia missing the final three months of the 2010 season after suffering a fracture in that location.

Ellsbury is hitting .299 with eight home runs, 31 doubles, eight triples and 52 RBI with a major-league best 52 stolen bases over 131 games this season.