Now that a missed season is a real possibility, the lockout could end the Boston Celtics’ Big Three era. It could potentially threaten Kevin Garnett’s career. It could mean that Ray Allen is 37 years old when the NBA returns, and Paul Pierce might be 35. And if all that’s not enough, a missed season could result in Danny Ainge scrambling to fill 12 roster spots for 2012-13. I don’t mean to exude pessimism, but these are now realistic possibilities.

“There will ultimately be a new collective bargaining agreement,” NBA Commissioner David Stern said after hearing of the NBPA’s decision. “But the 2011-2012 season is now in jeopardy.”

And for veteran teams that have few bodies under contract right now, like the Celtics, they could very well fall under the category of collateral damage associated with this lockout if it wipes out the entire season.

Beyond 2011-12, the Celtics only have three players under contract – Paul Pierce, Rajon Rondo and Avery Bradley.

So if the season were to be wiped out entirely, the C’s would have as many as 12 roster spots to fill.

The Miami Heat certainly didn’t complain after needing to fill 12 roster spots last summer. But there were extenuating circumstances. Two of the game’s biggest stars (and Chris Bosh) were all free agents at the same time. The trio decided to combine their powers. It was a combination of luck, circumstance and the persuasive powers of Pat Riley (not to mention the persuasive powers of South Beach).

The Celtics wouldn’t be so lucky. Even if the free agency classes of 2011 and 2012 were combined, which is what would happen after a missed season, there’s STILL not the type of star power to rebuild on the fly. Dwight Howard, Chris Paul and Deron Williams are the only superstars on the market. Two of them play Rondo’s position. The other, Howard, will have many other realistic suitors besides the Celtics. If Howard did sign with the Celtics, the Celtics could presumably re-sign Allen and Garnett to smaller contracts and join them with Pierce, Rondo and Howard to form an awesome starting five. But that’s assuming Howard signs. And the Boston Celtics historically don’t land high-profile free agents.

More likely, the Celtics are looking at a lengthy rebuilding process after the (rumored) 2011-12 season. The thought is sobering, but it’s reality. The final year of the Big Three era is in jeopardy, and the future is unknown.