Christmas Countdown: Dominant storyline

We've said the same thing three years running, but this is definitely the last rodeo for the Big Three ... probably. Brian Babineau/NBAE/Getty Images

Editor’s note: Over the next 12 days, we’ll countdown to the Celtics’ Christmas matchup with the Knicks (Dec. 25 at 12 p.m. ET) by hitting on 12 big topics facing the Green this season.

WALTHAM, Mass. -- There’s been so much talk about “windows” since the Big Three were united in Boston that you’d think Bill Gates ran the team. When Kevin Garnett, Ray Allen and Paul Pierce were united during the summer of 2007, most figured that window of opportunity was three years at best.

And ever since they won a title after less than 12 months together, the focus has been on whether they are too old to do it again. Few thought they’d still be together at this point, but one thing is certain: This is the last rodeo ... probably.

“It is [the last rodeo for the Big Three],” Celtics coach Doc Rivers admitted. Allen and Garnett will be unrestricted free agents after the season, and the expectation is the Celtics will begin turning over their roster by using that cleared cap space to splurge on the next generation of superstars.

“I was very honest with them about that," Rivers said. "That doesn’t mean we won’t have some of them back next year or not, but there’s the chance that we will not. And this is most likely our last shot. And I was honest with them about that. This has to be a team that looks at ourselves like we have to do it this year because this is our only year that we can do it. We may never be in this position again, as a player or as a coach. We have to try to take advantage of it.”

Despite flirtations with trades that could have overhauled part of the core -- even if the Big Three never seemed in jeopardy of being split up -- the Celtics are set to bring back their same playoff starting five from last season, with alterations simply to the bench.

Some will wonder if it wasn’t good enough last season, why would it be good enough this season? Can the Celtics get enough out of that aging Big Three to still hang with the young guns of the Eastern Conference? Especially after the Heat -- and their vaunted Miami Thrice -- knocked Boston out of the Eastern Conference semifinals last season.

“We didn’t get enough out of our team [last season],” Rivers admitted. “We just watched some film of that [Heat series before the team’s first practice session of the new season Friday]. Just to refresh all of their memories. [The Heat] were the better team in that series, but we made mistakes. And I wanted to remind them of that. I thought that was important.”

One encouraging sign is the high level at which the Big Three played last season. Garnett labored during the 2009-10 season, coming off of a knee injury, but seemed far less hindered last season. Allen posted career bests in field goal and 3-point percentages, all while becoming the NBA’s all-time leader in 3-point field goals. With a new four-year deal in his pocket, Pierce quietly put together another solid and consistent campaign.

Can the Celtics maintain that level of play? Allen turned 36 over the summer, yet he’s the least of the concern. Garnett will match that age in May and has put a lot of miles on those tires since being a preps-to-pro phenom. Pierce overcame an injury-filled 2009-10 season to play 80 games a season ago, setting a career high in field goal percentage (49.7).

Garnett acknowledged that nothing is a given at this stage of their careers.

“No one knows the certainty of the future, so we’re embracing this year as our last,” he said. Asked about his future, Garnett added, “I’m focused on this year and this year only. I’ll make other decisions later.

All three players gushed about the early moves in free agency, hoping bench additions such as Brandon Bass, Chris Wilcox and Keyon Dooling can help take the stress of the veterans. Concerns remain up front, where one year after leaning on an injury-riddled Shaquille O’Neal the Celtics will likely hang their hats on injury-riddled Jermaine O’Neal (who was limited to 24 regular-season games a season ago).

The Big Three -- along with point guard Rajon Rondo -- know the responsibility of leading this team falls heavily on their shoulders this season. They are prepared to shoulder the load.

“I like our team,” Allen said. “I feel very strongly about our chances. One of the things that we said is that we have the guys that are going to help us win. But you know, me, Paul, Kevin and Rondo, we have to make sure we play our best basketball. We have to be leaders and make sure that we do the right things at all times. That responsibility always falls squarely on our shoulders. We have to be better this year than we were last year.”

Because they most likely won’t get an opportunity next year to be better than they were this year.