ST. PETERSBURG -- B.J. Upton left the Rays' 6-3 loss to the Red Sox on Thursday night after injuring his left ankle in an outfield collision with Carl Crawford in the top of the fifth inning.
Upton was examined by team orthopedic Dr. Koco Eaton, who determined that Upton had suffered a left-ankle sprain. X-rays taken at Tropicana Field were negative and Upton is listed as day-to-day with a Grade A ankle sprain.
"I just rolled it. ... It's just day-to-day," Upton said. "We'll see how it goes the next couple of days, see how it feels and we'll work from there."
Dustin Pedroia hit a ball to the gap in left-center field that Upton and Crawford converged on at the warning track. Crawford made the catch for the second out, but he made contact with Upton. Replays showed that the Rays' center fielder drastically rolled his left ankle.
"I think we were both calling it," Upton said. "It was kind of one of those in between balls. ... It was just something we haven't dealt with much of the time. I tried to move out of the way of him. And I just kind of came down funny on my ankle."
Upton immediately went to the ground face down, kicking his right leg back and forth while keeping his left leg still. Rays head trainer Ron Porterfield and manager Joe Maddon rushed to Upton's aid.
"The way he's writhing on the ground, I was really concerned about it," Maddon said. "I've got like 500 feet to run ,and I'm not really used to that. But fortunately Ron Porterfield is very fast, so he got to him in good shape. By the time he turned him over, I felt like he was OK."
Minutes later, Upton was on his feet and he walked off the field on his one power, limping slightly as he went.
"I was definitely in a lot of pain," Upton said. "[I] didn't know what was going on. Once it cooled off a little bit, I was able to get up and walk off by myself. [It] definitely made it feel a lot better."
Ben Zobrist moved from second base to center field and Akinori Iwamuri came in to play second base and hit in Upton's ninth spot in the order.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.