BOSTON -- Boston Red Sox center fielder Jacoby Ellsbury left Friday's game holding his right arm to his body after he was injured sliding into second base in the bottom of the fourth inning.

The Red Sox announced it was a right shoulder injury, and that Ellsbury will be evaluated further. But a baseball source said Friday night that Ellsbury had sustained a dislocation or subluxation (partial dislocation) of his right shoulder. No timetable was offered as to how long Ellsbury will be out.

"It depends on how he responds," the source said.

A minor dislocation typically requires a minimum of four to six weeks, but if further evaluation reveals additional trauma to the shoulder, such as tears to the rotator cuff, labrum or other muscle or tendons, Ellsbury could be in jeopardy of missing months more.