Briefed on comments made by a somewhat disgruntled Glen Davis on Monday, Celtics coach Doc Rivers brushed aside Big Baby's concern about not having a defined role and sent a firm message back about what he can expect this season, according to an ESPN.com report on Tuesday.

Kevin Garnett appears to be very healthy as the Celtics begin training camp.

"I think Kevin needed some rest, some time off, and he took it, but he's ready for camp," said Danny Ainge. "He's in much better shape than he was last year in training camp. I think that KG got better as the year went on last season and we saw him moving much better in the playoffs than in the regular season."

The Celtics have waived Oliver Lafayette.

Lafayette played just one game with the Celtics last season, scoring seven points in 22 minutes in a 106-95 loss to the Milwaukee Bucks on April 14.

Rajon Rondo was ambivalent about participating on Team USA's roster, but he initially had his mind changed by his agent Bill Duffy.

"Physically, emotionally, he wasn't ready for it," Duffy said. "I feel bad because I was really pushing him to do it because of the experience and his stature."

"I just never got the sense he was committed to it the way some of those other guys were," Danny Ainge said.

"It was great to practice every day against the best young talent in the league, a veteran like Chauncey Billups and play for a Hall of Fame coach [Mike Krzyzewski]," Rondo said. "But some of these guys hadn't played since April. Lamar [Odom]  and I had just got out of Game 7. And next season is right around the corner. I feel like I had to take advantage of the opportunity I have right now to win another championship. It's not often you get to play with four Hall of Famers. Another couple of years and I won't have that."

Celtics' owner Wyc Grousbeck helped convince Danny Ainge that the team should pursue Shaquille O'Neal.

"The minute I heard Kobe [Bryant] say he had one more ring than Shaq, I said to Danny, 'Let's go get Shaq,' and it happened," said Grousbeck.

"This is a very, very proud bunch of guys, the champions from '08. And now with Jermaine (O'Neal) and Shaq and Delonte (West), who haven't been champions with us, this could be a good group. We've got huge challenges but we reloaded this summer. We really want banner No. 18."

The Celtics have invited former UMass star Stephane Lasme, Southern Indiana's Jamar Smith and LSU's Chris Johnson to training camp, according to sources.

Boston already has 15 players under contract for the 2010-11 season, making it unlikely that any camp invitees will make the regular-season roster.

The Celtics worked out Adam Morrison, Rashad McCants, Cuttino Mobley, and Trenton Hassell this week.

Adam Morrison isn't the only free agent to have worked out for the Celtics this week.

Cuttino Mobley, Rashad McCants and Trenton Hassell also auditioned for Boston, according to Adrian Wojnarowski of Yahoo! Sports.

Still searching for another shooter, the Celtics have Adam Morrison working out for their front-office and coaching staffs this week, league sources told Yahoo! Sports.

Morrison worked out on Tuesday and planned to do so again on Wednesday, sources said.

The Celtics aren?t close to deciding if they?ll make any kind of make-good contract offer for training camp.

Celtics center Jermaine O'Neal is coming off a max-level contract that he claims he didn't know put him among the NBA's highest-paid players.

O'Neal signed the seven-year, $126 million contract with the Pacers before being dealt to the Raptors and then the Heat.

"I didn't even realize until this summer that over the last seven years I was one of the top three paid players in the entire NBA," O'Neal said. "I never knew that.

"I never looked at that money as being pressure. To be honest, towards the last two or three years, I felt like I wasn't doing enough to earn my money. I'm very critical of myself."

The Celtics planned to retool their roster this offseason, but Miami's big move to sign LeBron James and Chris Bosh forced Boston's hand.

"We were already going to try and get better, get tougher," Grousbeck said. "But then the Miami thing just took it to a new level."

Boston added Jermaine O'Neal and Shaquille O'Neal to help with their rebounding.

"I don't have an assessment of other guys, but I do know that we needed size and now we're the biggest team in the league," Grousbeck said. "With [rookie] Semih Erden, we added three, 7-footers."