I think we now be officially worried about Perk's shoulder injury. Or, at the very least, the depth of the Center position. From Marc Spears:

Celtics center Kendrick Perkins probably won't be able to shoulder the load when training camp starts Tuesday.

General manager Danny Ainge said yesterday that Perkins isn't expected to participate at the beginning of camp after undergoing arthroscopic surgery on his left shoulder July 2, but he should be ready for the start of the regular season.

"He'll be trying to get through September," said Ainge, who added that the rest of the players on the roster are healthy. "I'm confident he will be in the starting lineup opening night."

With Perkins's status in doubt for exhibition games, it wouldn't be surprising to see Leon Powe start in his place. The Celtics also have newcomer Patrick O'Bryant at the position.

"I'm comfortable at the center position," Ainge said.