Never thought we’d ever be discussing this topic in the year 2011.

The Boston Celtics: potential 2012 NBA champions?

For Paul Pierce, Kevin Garnett, and Ray Allen, it’s Year 5 as a unit. What was once the Big Three, Part 2, is now the Big IV. Then again, Rajon Rondo’s emergence as a genuine NBA star is a large part of the reason the Celtics are still being discussed with the NBA’s elite. There would be nothing to talk about if the Celtics had a mediocre point guard.

Still, Messrs. Pierce, Garnett, and Allen were universally assumed to have a three-year window of opportunity to produce a championship, no matter who surrounded them. They got the job done in the first year, which certainly justified all of Danny Ainge’s maneuverings. An injury to Garnett damaged their chances of winning in the second year. An untimely injury to Kendrick Perkins hindered their opportunity to win in the third year (although let’s not forget that Game 7 in LA turned from plus-3 to minus-6 in one lightning 90-second span of the fourth period). Last year they were just whupped by Miami.

Ainge could have broken up the gang in some way, acknowledging the end of a brief era and moving on with a new personnel plan. Doc Rivers could have taken a personal sabbatical, watching his four offspring play, dispensing a little punditry and, finally, choosing among the lucrative coaching offers that would surely come his way at the conclusion of the 2011-12 NBA season.

Neither of these things happened.

Nope, Danny and Doc remain one of the NBA’s closest management-coaching duos and each appears to be of the belief that winning an 18th Celtics championship is an attainable goal. No, they’re not a prime favorite, but the idea of Boston celebrating after the final game of the upcoming season isn’t being dismissed as ludicrous, either.

However …

A starting lineup that includes a 33-year-old, a 34-year-old, a 35-year-old, and a 36-year-old?