‘It was a sigh of relief, no doubt’

Doc Rivers and the rest of the Celtics gratefully exhaled when they learned of Paul Pierce’s X-ray results, which didn’t indicate any serious damage to his left foot or ankle.

Pierce got his foot tangled under Caron Butler during Monday night’s victory in Washington, and the C’s captain grimaced in agony. Rivers, though, said Pierce is day-to-day and could return as soon as Sunday against the Magic.

Pierce missed his sixth game of the season last night against the Heat. He was replaced in the starting lineup by Tony Allen, who had averaged 10.7 points in his previous three games off the bench.

“I was worried about him when he did it,” Rivers said. “It looked awful, but just watching him walk around the locker room [Monday] at halftime, I didn’t think it was a severe injury. He did play in the second half a little bit, but then after the game, he said it bothered him.

“When I got the report back, it was a sigh of relief, no doubt.”

Despite the short-term good fortunes, Rivers has not shied away from his long-term concerns. The Celtics have missed 111 man games this season, and they can’t progress as a group without their main contributors in the lineup.

It’s a veteran squad filled with experienced winners, but there is a pressing need to develop on-court chemistry before the start of the playoffs in mid-April. Best case scenario, the Celtics will only have about 30 regular-season games to mesh before the postseason.

“I am concerned by all the injuries, clearly,” Rivers said. “Obviously, you don’t want that, and it does hurt your continuity as a group. It’s been very difficult to get any continuity as a team.

“Every time we think we’re about to get it, something happens.”

jeff.howe@metro.us