"Josh was evaluated today at the Massachusetts General Hospital by the Red Sox medical staff, including team foot and ankle specialist, Dr. George Theodore," read a statement issued late Tuesday by team medical director Dr. Tom Gill.
"Josh experienced pain in his ankle while pitching last night. His examination was consistent with an ankle sprain. An MRI was performed that confirmed no other injury to his ankle tendons, or his Achilles tendon. We will re-evaluate his symptoms and availability later this week."
Beckett worked 3 2/3 innings, fanning six and walking one while allowing three hits.
The Sox announced prior to Tuesday's contest that Beckett will not make his next scheduled start, which was supposed to be on Sunday against Tampa Bay. Instead, John Lackey will go on Friday, recent call-up Kyle Weiland will take the hill on Saturday and Jon Lester starts on Sunday.