What now?

Bill Belichick is without his biggest impact player for the rest of the season, putting New England at a disadvantage it's never experienced under his watch

Apples and grapefruits.

That's how Patriots coach Bill Belichick described the difference between his offense in 2001 and his offense in 2008, during his "State of the Union" Monday afternoon press conference.

Drew Bledsoe's injury paved the way for Tom Brady seven years ago, and after getting smashed in the knee on Sunday against the Kansas City Chiefs, Brady now finds himself on the other side of that season-ending surgery. Brady will miss the rest of the year with a torn ACL in his left knee, leaving Matt Cassel as his replacement.

I know what you're thinking. Brady did it. Why not Cassel?

Apples and grapefruits.

When Bledsoe went down in '01, Brady had already made a name for himself within the organization. Some close to the team that preseason said that Bledsoe was only starting because of the huge contract he had signed in the winter of 2001. It should also be noted that there was a lot less pressure on Brady then, as expectations for the Patriots weren't as high as they are now.

Cassel comes into a situation where he hasn't played quarterback in a full-time role since high school, some eight years ago. He spent four seasons watching Carson Palmer and Matt Leinart light up the scoreboard at USC, and while it's not terrible company, Cassel saw more playing time as a receiver (wide receiver in 2001, and tight end in 2003) in college than he did under center.

Now, the 7th rounder from the 2005 draft is being asked to fill the shoes of a two-time Super Bowl MVP and the reigning NFL MVP after spending seven straight years holding a clipboard. Sure, Brady was asked to win in 2001 when he came off the bench for an injured Bledsoe, but nobody expected a Super Bowl ring. And many wanted to rid themselves of No. 11's immobile antics in Foxboro anyways. People were actually glad to see Brady then.

Raise your hand if you would prefer Cassel over Brady now.

Not even Belichick can convince all his players to say the right things about this one. Wide receiver Randy Moss admitted he was like a kid in a candy store, constantly peeking back to see if Brady was coming back onto the field Sunday against the Chiefs.

Instead, Brady left everyone waiting, and Cassel finished the game at quarterback with a 17-10 Patriots win.

If given the choice to start 0-1 with a healthy Brady, or 1-0 with Cassel for the rest of the season, you wouldn't find anyone on the planet willing to take on the latter. But to be fair, if anyone is going to overcome a loss of this nature, it's going to be Belichick. But he can only do so much.

Even Belichick said it during his Monday press conference. The two most important attributes of an NFL quarterback are decision making and accuracy. Belichick is the mastermind. Cassel must now execute. Easier said than done.

Not to take anything away from Belichick, because he will go down as one of the greatest coaches of all time, but for the last seven seasons, it's been Brady executing on the field. It's been Brady that's thrown touchdown passes and led two-minute drills in Super Bowls.

So does Belichick owe all his success to Brady? No way.

Then does Brady owe his rings to Belichick? Absolutely not.

Both go hand in hand. Both work together to be successful. But is Belichick's job easier with one of the greatest quarterbacks that's ever lived running his plays, rather than a full-time backup taking the snaps? No doubt about it.

To say it's not, would be taking everything Brady has done in his NFL career, and saying "he wasn't that great." To say that the Patriots' season can be saved just because "defense wins championships" or because "Belichick is a genius" is a slap in the face to the guy who's gone out and done nothing but execute with mere perfection since being called upon in 2001.

Defense does, in fact, win you championships. Belichick is brilliant. But the Patriots still need a quarterback.

And they're not going to win with grapefruits.