Semih's sore shoulder

(AP Photo/Mary Schwalm)

Semih Erden blocks a shot against the New Jersey Nets in last week's exhibition finale.WALTHAM, Mass. -- With opening night rapidly approaching, Celtics coach Doc Rivers admitted Sunday that rookie center Semih Erden is questionable for Tuesday's game against the Miami Heat with a sore shoulder.

"Semih is questionable; I don't know what he can give us, honestly," said Rivers. "He may play, he may not. His shoulder is going to take some time."

Rivers initially hinted this weekend that Erden had been battling a previously undisclosed shoulder ailment, explaining a bit of his dip in consistency late in the preseason. Erden appeared in all eight preseason games, averaging 5.8 points, 4.4 rebounds, and 1.3 assists over 21.8 minutes per game. He scored 13 points in his NBA debut against the 76ers on Oct. 6, but never topped seven points the rest of the way.

The injury hasn't prevented Erden from participating in recent practices and he's actually stayed on the court for additional work after most sessions, but Rivers admitted that the shoulder injury requires monitoring by the team.

"I think he hurt it in a game, but it was hurt before he got here and then he just re-injured it," said Rivers. "And playing against [Shaquille O'Neal] every day in practice can't be a lot of fun."

Erden's injury could thin out some of Boston's depth up front on opening night, especially with starting center Kendrick Perkins sidelined into the new calendar year after offseason knee surgery. With Shaquille O'Neal expected to stat opposite Kevin Garnett in the Celtics' frontcourt, Boston would boast Jermaine O'Neal, Glen Davis, and Luke Harangody as big bodies off the bench.

Jermaine O'Neal (left wrist) got another thumbs up from Rivers Sunday, but Boston's helmsman admitted it was a lighter session and hard to gauge progress. Jermaine O'Neal said Friday he expects to play against the Heat.

"Jermaine is looking better, he had a good practice again [Sunday]," said Rivers. "But we didn't do much today... I think he'll be good and play in the first game."

Rivers hadn't been so optimistic last week, when the injured wrist kept Jermaine O'Neal off the court for a seven-day span. He returned to practice Friday, sporting a brace and revealing he tore cartilage in the wrist while taking a first-quarter charge in an exhibition win in Toronto.

With rookie Avery Bradley still sidelined by ankle soreness, the Celtics could be limited to 11 players Tuesday, with Delonte West set to begin a 10-game suspension to start the regular season.