The Celtics are bringing the band back together for one more year and no one seems particularly thrilled with the notion of turning into a version of the mid 2000’s Pistons; a.k.a. the team that was one of the toughest outs in the league, but didn’t have enough to get back to the summit.

This is understandable in the wake of the Celtics five-game loss to Miami in the Eastern Conference semifinals. The Heat have moved past the Celtics ... and the Bulls may have too. Both are young and growing and don’t seem likely to take a step back anytime soon. Comparisons to the end of the original big three era are everywhere and well, the whole thing is beginning to feel stale and injury-prone.

There are, of course, practical reasons for team president Danny Ainge to follow this path. Assuming Ray Allen either picks up his option or signs an extension, the Celtics will have about $64 million committed to six players, likely leaving them well over whatever salary cap structure is hammered out in the collective bargaining agreements that hopefully won’t threaten next season.

The uncertain financial landscape plays a part. There have been glimpses of ideas — hard caps, salary rollbacks, a new franchise player designation — but until all the details are finalized, it’s difficult to consider a wholesale rebuilding project under those circumstances.

The Celtics have planned for the last few seasons to keep their books as clear as possible for the summer of 2012 when Kevin Garnett’s contract expires. That’s part of the reason Ainge traded Kendrick Perkins and it also played a role in not offering three years to Tony Allen at the outset of free agency last summer.

“Maybe if I made that offer initially [he would have re-signed], but we were trying to maintain our flexibility,” Ainge said on Friday in an end of the year exchange with the press. “It wasn’t about money. It was about years and flexibility. If I had done it sooner he might not have been wooed by Memphis.”

Ainge’s reluctance may have dealt this season’s championship hopes a fatal blow, but we’ll never know for sure. What we do know is that the team’s financial picture could be very clean after next season. Garnett is in the final year of an extension that will pay him over $21 million this season. If Allen exercises his option, he will be a free agent, as will Jermaine O’Neal.

As it stands now, the Celtics are committed to less than $30 million in salaries for 2012 even if they pick up Avery Bradley’s option years on his rookie contract with Rajon Rondo and Paul Pierce the only other players under contract. That’s a lot of room to make a run at a prized free agent, and the name on everyone’s mind is Dwight Howard who can become a free agent after next season.

They won’t have that much room under the cap once you factor in cap holds, draft picks, and contracts for players like Jeff Green, who is a restricted free agent this summer and in line for a decent payday. Glen Davis, who is an unrestricted free agent, will also get paid whether it’s here or somewhere else, but perhaps not as much as he had envisioned.

As for the nuclear option, fans have concocted deals for Chris Paul or Howard, and as far-fetched as they may seem, Ainge is obviously not afraid to make a big strike if he feels it is the right move.

Barring a summer blockbuster, the Celtics will return the core of a team that won 56 games, ranked second in defensive efficiency and was generally considered among the handful of legitimate championship contenders all season long. Of course, it will also be a year older and Ainge understands that the Celtics can’t rely on Pierce, Garnett and Allen duplicating their 2011 seasons, which were all strong.

“I know this about the big three: they still have a lot of basketball in them,” Ainge said. “How much can they carry a team, [and be] 20-point a game scorers, I don’t know. I do know they’re still very talented, but we need to have talent around them.”   

Let’s start with the first part of that quote. It would seem that the big three do in fact have more basketball in them, even at their advanced ages. Pierce had arguably his best season of the era, shooting a career high in true shooting percentage (which accounts for 2’s, 3’s and free throws) while cutting down on his turnovers.

Allen had an insanely hot winter, and while he cooled off down the stretch, that probably owed more to a general malaise that set in over the offense. The concept of Ubuntu may be dated, but offensively the Celtics truly are what they are because of each other. When one of them slumps, it has an effect on all of them, particularly Allen who relies on his teammates for shots, screens and spacing.

Garnett returned to form defensively and on the boards and while his minutes were strategically kept down, he had a ruthlessly efficient season shooting the ball. Garnett was arguably more responsible than anyone for the Celtics regular season success.

The playoffs, though, told a slightly different story, which is at the root of the why-is-Danny-bringing-them-back angst.

Allen was great against the Knicks and pretty good against the Heat. The only problem was Dwyane Wade was either the best player in the series or tied with LeBron James for the honor. Allen has contained Wade well over the years and has worn him out running around screens, yet Wade may have figured this one out.

He averaged 28 points and almost eight rebounds per game, while living at the free throw line, taking almost a dozen per game. Allen shot the ball well, but in the absence of someone who could come in and cool Wade off (insert Tony Allen groan here), Ray Allen was left to try to keep up with the younger, more athletic player.

Pierce, meanwhile, hung with James in Games 1 and 4, outplayed him in Game 3 and was outplayed himself in Game 2 when he injured his Achilles. James decisively won the clincher when he went crazy down the stretch and Pierce spent the night in foul trouble. Pierce has battled James throughout his career. He’s won several of those matchups and is certainly capable of getting the better of him on a game-by-game basis, but at this point LeBron is simply better, as is Wade. 

How much better is the issue. On some level this is basic. Wade and LeBron are in their primes and balanced against the length of a series, they’re advantage over Pierce and Allen should be assumed.

The Celtics knew that, even expected it some degree, but the counter involved Garnett outplaying Chris Bosh and Rajon Rondo doing damage and forcing coverages against the point-guard less Heat. Instead, Rondo got into foul trouble in Game 1, dislocated his elbow in Game 3 and never really got into any kind of a rhythm.

Despite his brilliant Game 3, which was the best game by any Celtic player during the playoffs, Garnett played Bosh to a draw, at best. Even more than Pierce and Allen, this really dives into the issue because there were times when Garnett absolutely destroyed Bosh. But late in games, Bosh had more in the tank while Garnett appeared, well, exhausted.  

So, has Miami’s big three officially surged past Boston’s? Yes, and they appear to be waving a plume of smoke in their dust. Ainge recognizes this, which is why his first response to the question: What’s the biggest area of need was “talent,” specifically scoring talent.

“Scoring droughts have been a problem we’ve had the last few years,” Ainge said. “For whatever reason, we’ve had too many scoring droughts at crucial points in games and that’s hurt us.”

Part of the blame can be pinned to a supporting cast that never developed any cohesion through injuries to Delonte West, Marquis Daniels, Jermaine O’Neal and Shaquille O’Neal. For whatever reason, Jeff Green and Nenad Krstic failed to provide consistent production and Glen Davis faded badly down the stretch and in the playoffs.

The result was the big three and Rondo playing too many minutes during the regular season and also having to play too many minutes while either trying to build a lead or come back from a deficit. The supporting cast is the area Ainge wants to address and he wants to do it not only to provide relief, but also to bring down his veterans’ minutes.

“I think that’s an unreasonable expectation to expect them to play the minutes they played this year,” Ainge said. “That was not in our plans at all this year for them to play as many games as they did and as many minutes as they did. I think our plan going into next year will be less games, less minutes.”

Green is expected back and Ainge made his intentions clear to try to re-sign Krstic. West, who may have offers from other teams, would also be welcomed back. Avery Bradley will have a chance to compete for a role and the Celtics love his athleticism and defensive tenacity. Whether Davis comes back another tour is open for debate -- it’s likely the Celtics will let the market come back to them as they did when he was restricted free agent after the 2009 season.

Ainge seems to be pinning much of the hopes of the future on Green, who displayed hints of promise with long bouts of inconsistency and several unfortunate turnovers in the playoffs. 

“We know what Jeff Green is,” Ainge said. “He’s a highly efficient offensive player who plays good defense. That’s what we need, and he’s young and I think he’s just going to get better because of his character and work ethic.”

Ainge pointed to Green’s points-per-possession in an interview with The Big Show on Thursday, but most available metrics don’t paint Green as an efficient offensive player. He’s a 30 percent 3-point shooter for his career, who doesn’t get to the free throw line very much. He’s also below-average rebounder for his size.

Still, Green did play marginally better in Boston than he did in Oklahoma City, albeit in less minutes. If Ainge is right that Green can thrive in a larger role, then that would go a long way toward leveling the court in terms of youth and athleticism.  

But more help is needed. The Celtics have the 25th overall pick in what is considered a weak draft. There are also no marquee names in this year’s free agent class, and again, no one yet knows the rules by which they can be signed. But there are a handful of high-scoring perimeter players available like Jamal Crawford and J.R. Smith, and also veteran defensive stoppers like Shane Battier and Tayshaun Prince. He may beyond their resources, but O.J. Mayo is expected to be a trade candidate.

The free-agent big-men pickings are slim with Tyson Chandler the main prize, but probably too rich for the Celtics, given their cap situation. Players ranging from Sam Delambert to Kenyon Martin and Kwame Brown are also available.

That’s why re-signing Krstic makes sense, along with the hope that Jermaine O’Neal can return and provide more regular season minutes than he did last season. Trying to solve two main areas of need will be difficult for a team relying on cap exceptions to sign players. If either of those things doesn’t happen and Davis doesn’t return, this area will become a priority at the expense of adding more scoring and athleticism.

Finally, there is the hope that Rondo can return refreshed and invigorated after spending the season battling multiple injuries to his feet, hands, back and obviously his shoulder. Rondo’s played a lot of basketball in his short career and an extra month off will probably do him a world of good.

Early in the season he was considered among the elite point guards in the game and he’ll have to return to that level for the Celtics to have a chance to compete for a title.

But really, this all comes back to the big three again.

“Those vets aren’t regular vets,” Rondo said after Game 5. “They do a great job of taking care of their body. They work the hardest on the team as far as conditioning, I’m not worried about their health but it’s the [length] of the season. So if we can get some young guys in here that can pick up the load in the regular season, we’ll be fine.”

If Allen, Pierce and Garnett can duplicate, or come close, to last season’s production and if Rondo comes back and has a monster season, then the Celtics can compete for one more year provided Ainge hits a home run in free agency and Green develops into a sixth man of the year type of player. If any one of those areas comes up short, the Celtics could slide into the dreaded nomad land of being good, but not nearly good enough, somewhere between the Pistons of old or the Magic of current times.

Competing for a championship is not impossible with this group, but there’s a lot of ifs, which is why 2011-12 may ultimately wind up being remembered as a bridge year from one era to the next.