What to do about Matt Cassel may be the biggest question the Patriots face in the offseason. Much of it, of course, depends on Tom Brady’s recovery — another question.

The Providence Journal / Glenn Osmundson

I never played when I didn’t want to be the best out there every night. Not once.

—Larry Bird, in an interview published in the January issue of Esquire magazine

Tiger Woods is the same way. So was Michael Jordan. And is there any doubt that Ted Williams wanted to get a hit every time he stepped to the plate?

That’s the way the very best play the game.

That’s the way Tom Brady always has played. And there’s no reason to think he won’t play that way in 2009. Still, one wonders…

Brady will be 32 next August. When last we saw him — truly saw him, that is; the one half of one quarter that he played this season doesn’t count — he was at the top of his game, the best quarterback in the business, one of the best ever, ranking right up there with legends like Joe Montana and Johnny Unitas.

He had set an NFL record in 2007 by throwing for 50 touchdowns. Already a two-time Super Bowl MVP, he was voted the league MVP after leading the Patriots to a perfect, 16-0 regular season. His 6-yard TD pass to Randy Moss with 2:42 left to play in Super Bowl XLII should have brought the Patriots their fourth championship in seven years, except that the New England defense couldn’t keep the Giants from driving 83 yards to the winning touchdown in the final minutes.

But that was then, and this is now.

Now he’s recuperating from extensive surgery on his left knee, and the pace and quality of his rehabilitation and recovery are being hotly debated.

While Brady attempts to keep his glamorous private life as low-key as he can, when your Significant Other is world-renowned supermodel Giselle Bundchen, it’s easier to avoid the Giants pass rush than it is the paparazzi. He’s been photographed with her on the streets of Paris and New York, as well on the beach in Costa Rica and — well, you get the idea. When you’ve been leading a globe-trotting lifestyle, how tough is it spend time in the weight room, or studying the playbook? Especially when, unless he invested with Bernie Madoff, Brady should be financially set for life?

Which brings us to Matt Cassel, Brady’s understudy who filled in so capably this season.

There are only good things to say about Cassel, who led the Patriots to 11 wins, despite not having started a game since he was in high school. He improved with every game in both his decision-making and execution, and so has put himself in position to receive a huge salary bump next season, whether in New England or, more likely, elsewhere.

But there’s this to consider for those teams in search of a quarterback who are certain to throw money at him this offseason, or, if the Patriots decide to slap the franchise tag on Cassel make enticing trade offers to New England of players and/or draft choices:

With the Pats, Cassel has benefited with brilliant coaching. Much more often than not, what he expected to see from opposing defenses, he saw. To his credit, he became increasingly adept at recognizing coverages and blitzes and at executing the throws to beat them.

With another team, he may not be as well-prepared. Nor as well protected. As a unit, the Patriots’ offensive line of Matt Light, Logan Mankins, Dan Koppen, Stephen Neal, and Nick Kaczur is a solid group. Throw in the fact that, if Cassel goes elsewhere, he won’t have top-quality receivers like Randy Moss and Wes Welker, nor someone as dependable as Kevin Faulk catching the ball out of the backfield.

The point is, as good as Cassel has looked for the Patriots, he may not look that good wearing another uniform in 2009.

Speaking of looking good elsewhere, Bill Belichick’s “coaching tree” has undergone some serious pruning.

Two of his former defensive coordinators, Eric Mangini and Romeo Crennel, have been fired from their head coaching jobs with the Jets and Browns, respectively.

Add the fact that highly-regarded, former offensive coordinator Charlie Weis’ job situation at Notre Dame is tenuous, given that the Fighting Irish are 10-15 over the past two seasons — his third and fourth in South Bend — and you have to wonder if all that will have an adverse effect on the prospects for moving up of current Pats offensive coordinator Josh McDaniels.

McDaniels is his own man, but the lack of success of Mangini, Crennel, and Weis could be cause for concern for someone thinking of hiring the 32-year-old McDaniels as head coach.

While Patriots fans can bemoan the ill fortune that has left their favorite team as the only club to finish 11-5 and miss out on the postseason since the NFL expanded its playoff format to 12 teams in 1990, a review of the Pats’ performance against playoff teams this season doesn’t indicate a return to the Super Bowl if they’d managed to get into the “tournament.”

New England was only 2-4 against playoff teams. Three of those losses were lopsided, and two of them came at Gillette Stadium — a 38-13 trouncing at the hands of the Dolphins, and a 33-10 pounding by Pittsburgh.

The Pats also were routed at San Diego, 30-10, and lost at Indianapolis, 18-15. Their two wins over teams playing in the postseason were an impressive, 48-28 victory at Miami — the AFC East champion Dolphins’ only loss in their last 10 games — and a 47-7 humiliation of the Cardinals, who wanted no part of either the Pats, or the snow, the Sunday before Christmas in Foxboro.

We’ll never know how the Pats would have done in the playoffs, but expecting a fifth Super Bowl appearance in eight seasons certainly would have optimistic.

jdonalds@projo.com