Jermaine O'Neal, West miss practice

WALTHAM, Mass. -- Boston Celtics center Jermaine O'Neal sat out his second straight practice Monday with a tight left hamstring, an injury coach Doc Rivers said will keep him sidelined for the rest of the week as a precautionary measure.

O'Neal called the injury "minor" and preferred to call his absence "day to day." He also expressed a desire to participate in the approaching exhibition slate in order to develop on-court chemistry with his new teammates. If he sits for the week he would miss the Celtics' first two exhibition games.

At this time of year, Rivers is taking no chances, and that included with Delonte West, who also sat out Monday's session with back spasms. Rivers dubbed the guard day to day and suggested he could be back on the court as early as Tuesday.

"I just think that, when you look at [Shaquille O'Neal] and Jermaine, and think they can play 82 healthy games -- that'd be nice, but we have to be ready for them to miss a couple games and be able to play through it," Rivers said Monday. "That's why guys like Luke [Harangody] and Semih [Erden] are so important. Until [Kendrick Perkins] comes back, they're going to have to play, one of them at least.

"The first 10 games, we don't have D-West [due to suspension]. So someone else might have to play, or we go with a shorter rotation to start the season by playing Paul [Pierce] and Ray [Allen] more minutes, just until D-West comes back. That's up to how our other guys work out and how well they play."

Therein lies the silver lining for Boston. Injuries Monday allowed the team to bump Shaquille O'Neal up to the first team and get another extended look at him with the first unit (as Rivers continues to weigh which of the O'Neals should open the season as the team's starting center), while both Erden and guard Von Wafer shuffled up to the second unit for extended work after spending much of camp with the third grouping.

For all the excitement around Boston's second unit so far this preseason, it's clear that injuries have the potential to make things difficult.

"Up until today, the second unit looked good," said Rivers. "When you have D-West and Shaq and Nate [Robinson] and Marquis [Daniels] on that second unit with [Glen Davis], that's pretty good. But today because of injuries, it wasn't a fair fight."

Jermaine O'Neal watched Monday's session from the sideline and stressed that he still wants to be in on all the team activities, especially as he seeks to find his role on this year's squad.

"I'm not really concerned about [the hamstring]," O'Neal said. "I'm more concerned about being in with the guys and getting that chemistry up. The first four days [of camp] were really good. Wednedsay, Thursday, and Friday [at camp], I was just starting to get comfortable with the system, the philosophies that Doc wanted and also playing with those guys. It's very difficult to learn areas of an offense and defense when you're not in there. That's probably the most frustrating part about it, but I don't have any doubt in my mind that I'll be back in there soon."

Then he hauled in a rebound over Shaq at the very end of a scrimmage session and felt a burning sensation in the hamstring as he turned to head up court. He sat out Saturday's session in Newport as well.

"Holding up Shaq every damn day, it's crazy, you do it four times a year [when you play against him], but every day in practice is difficult," O'Neal said. "I boxed him out, got the rebound and I went to turn, and run up the court and that's when I felt a little burning sensation."

Still, O'Neal again stressed that the injury was not serious.

"If it was serious, I wouldn't be able to walk around and do the stuff that I'm doing," said O'Neal. "We're just making sure that I'm ready on Oct. 26."

That's the night the Celtics open the 2010-11 season by hosting the Miami Heat. As Rivers noted, that's the date on everyone's mind.

"I think if this was a young team, they would start getting excited about the exhibition games," said Rivers. "But I would almost wager that, if you ask them when the exhibition games are, they would have no idea. I don't think they look forward to exhibition games. We need them this year, just to get guys on the floor and figure things out. But other than that, it's Oct. 26. I guarantee they know that date. Heck, exhibition games, I don't even know when they are."

Chris Forsberg covers the Celtics for ESPNBoston.com. Follow him on Twitter.