Pierce is day to day with a strain

“We were concerned after watching the injury and seeing the soreness on Paul’s foot this morning and what it looked like on TV,’’ said Ainge. “I was worried, so I was very relieved to hear it was a sprained mid-foot and that he’ll be back soon.’’

Pierce left Monday’s 99-88 victory after Butler landed on his foot during a scramble for the ball with 2:01 left in the first quarter. Pierce, whose foot bent awkwardly under Caron, limped to the bench and was attended to by trainer Ed Lacerte but did not go to the locker room.

He returned to the game and played the final 7:53 of the second quarter as well as 10:24 of the third before sitting for the entire fourth quarter because coach Doc Rivers thought he was hurting.

Pierce was not examined until late yesterday afternoon and team doctor Brian McKeon did not receive the test results until approximately 5:45 p.m. The Celtics medical staff reviewed the results, examined Pierce for a second time, then made the diagnosis.

Earlier in the day, there was speculation - fueled in part by a Twitter post from teammate Shelden Williams - that Pierce broke his foot, information that Ainge called “way premature.’’

Pierce had an ice pack on the foot following the game and called the injury a sprain, but privately team officials feared it was much worse.

This is Pierce’s second injury in a month. He missed five games in December and January after having an infection drained from his right knee.

“When he’s ready, he’ll be ready,’’ Ainge said. “I think we’ll know. Again, his long-term health is the most important thing, and yet when he’s ready, he will be allowed to play. I don’t know when that is.’’

The tweet by Williams yesterday afternoon read: “Man when it rains it pours!!! Yall will find out what I mean soon!!!!’’

Before the test results were known, Ainge had said, “I know all of this was started because of some Twitter post from Shelden, and people are worried but we don’t know anything yet.’’