It had all the pomp of a Fenway Park opener, from the American flag draped over the Green Monster to the twin first pitches thrown by retired Tim Wakefield and Jason Varitek. And it produced a lopsided victory for a Red Sox team that needed one in the worst way.

But it also featured a look the Sox hoped never to see again from Jacoby Ellsbury.

It was a grimace reminiscent of when Ellsbury broke five ribs in an April 11, 2010, collision with then-teammate Adrian Beltre. Ellsbury missed all but 18 games that season, and without their leadoff-hitting Gold Glove center fielder, the Red Sox missed the playoffs.

So, when Ellsbury walked off the field, his right arm pinned to his chest, in the fourth inning of yesterday's 12-2 win over the Tampa Bay Rays, the Red Sox held their breath. And when he left Fenway to go for tests at Massachusetts General Hospital, they only could hope his right shoulder injury looked much worse than it actually was.

"That looked painful," said David Ortiz, who winced and shouted an expletive after seeing the replay on a clubhouse television. "Hopefully things don't go the way it looked like in the video. He's our leadoff hitter. You're not going to get any better by losing him for a while."

Initial indications last night were that Ellsbury suffered either a full or partial dislocation of his shoulder, according to a baseball source. A timetable hasn't been set for his return, but he likely will miss a minimum of several weeks.

Ellsbury's right arm was trailing behind his body as he slid into second base to try to break up a double play in the bottom of the fourth inning. Rays shortstop Reid Brignac leaped in the air to make the pivot and landed with his full weight on Ellsbury's shoulder.

By the time manager Bobby Valentine got to second base, Ellsbury was writhing on the dirt. Shortly thereafter, when Ortiz went to check on him in the trainer's room, Ellsbury was having difficulty raising his arm high enough to take off his jersey.