It's the most wonderful time of the year

WALTHAM, Mass. -- Boston Celtics coach Doc Rivers is going to have more trouble sleeping on Christmas Eve than most kids in Boston. And while he fully acknowledges disappointment in the fact that he'll wake up in a New York City hotel room feeling a bit like Kevin McCallister without his family, that pain will be diminished ever so slightly by the gift waiting for him: the return of honest-to-goodness NBA basketball games.

"It's great, it really is," Rivers said as a season that nearly wasn't finally nears tip off. The Celtics and New York Knicks meet in the first of five Christmas Day games, ushering in the official start of the 2011-12 season on the grand stage of Madison Square Garden.

"It's been a long time coming, as far as I'm concerned," said Rivers. "The fact that it's Christmas and we're talking about our first game of the year, that's amazing to me. Even though this training camp was short and we played only two preseason games, at the end of the day, it's time to play. And I think everybody is ready to play. I am as eager as I've ever been as a coach and I don't do anything, I just sit on the sideline. But you feel that, and I know the players feel that."

There's been a few grumbles in the Celtics' locker room about playing on Christmas (no different than in years past), but Rivers has constantly reminded his team that 1) It's just good to be playing basketball again, and 2) Playing on Christmas Day is a bit of a tip of the cap from the league.

"We're all fortunate, man," said Kevin Garnett. "You playing on Christmas, it says you're one of the best, or the league considers you one of the best. Either that or you're one of the most entertaining. I like to think we're either one. ...

"I haven't celebrated a lot of Christmases, but being at Madison Square Garden on Christmas is pretty exciting, so I'm embracing it."

Garnett was among the most vocal in expressing displeasure at a rushed start to the 2011-12 season. After enduring a five-month lockout, players and owners came to agreement on a new collective bargaining agreement in late November. But in order to start a condensed 66-game season on Christmas, the league trimmed training camp to two weeks and two preseason games, leaving teams scrambling a bit just to fill out their rosters and be ready for this day.

For his part, Rivers has instilled a "no excuses" mantra. He stresses to his players that the other 29 teams in the league are dealing with the same hurdles. In fact, Boston's continuity from having its core together for the past five seasons could actually give the Celtics an early-season edge over the competition.

That includes the Knicks, a team that cobbled together its own Big (Apple) Three this offseason, signing 7-foot-1 center Tyson Chandler to join a frontcourt that already featured Amare Stoudemire and Carmelo Anthony. Rivers knows his team is facing a "tall" task.

"They're long," said Rivers. "To me, they remind me of the [2010-11] Lakers in some ways. They go with their Bynum (Chandler), Gasol (Stoudemire) and Odom (Anthony) almost -- because that's a big lineup. Carmelo is huge; I don't think people realize how big he is. Then you have [Chandler and Stoudemire] so they have length now. And that's something they didn't have. They were small last year; now they're big."

One of the biggest questions surrounding the Celtics entering the new season is whether they have enough size. Jermaine O'Neal is the only legitimate and proven center on the roster with D-League standout Greg Stiemsma the only true backup at that position.

The Celtics are hoping their surplus of power forwards will offset that lack of pure height (even if Rivers joked Friday that a 7-footer was at the top of his Christmas list). Expect to see Kevin Garnett shuffle up to center while Boston mixes and matches with newcomers Brandon Bass and Chris Wilcox.

Maybe the other biggest question is what Boston will get from its bench. In addition to Bass and Wilcox, the team brought in veteran Keyon Dooling to back up Rajon Rondo, but the loss of Jeff Green leaves a real void in the reserve unit. The Celtics are hoping a healthy Marquis Daniels can pick up where he left off last season before a freaky spine injury ended his season, and maybe a younger player like Avery Bradley can emerge. Mickael Pietrus cleared waivers Saturday, but won't be able to join the team until passing his physical, set for Monday.

For all the continuity among Boston's starters, the bench is still putting it together, but they like what they see early on.

"We've got some depth, in my opinion," said Dooling. "I think we've got a lot of interchangeable parts. We've got a lot of guys who have some experience in our league -- that always helps when guys go down. I think our core guys, they just bring so much, so many other intangibles that you expect role players to bring -- our main guys bring them every day. So it's been a good transition, but we definitely have a lot of improving to do."

The next four months are going to be wild as Boston plays 66 games in 124 days. Given that a 149-day lockout threatened the season, the Celtics are fine with learning on the fly. At least basketball is back.

And to Rivers and his players, that's all that matters. That's the greatest gift of all this season.

Chris Forsberg covers the Celtics for ESPNBoston.com.