The sum very well might be greater than its parts, but in the NFL, not all parts are created equal. Because of talent, positional importance or depth, certain players carry greater responsibility for their teams. On a Patriots squad teeming with stars, deciphering just who bears the largest burdens is anything but simple. How can fearless slot receiver Wes Welker, the ultimate underneath option who has more catches than anybody the last two seasons, not be among the five most critical players? Or Adalius Thomas, who defines LB versatility? While many deserve recognition, these five particularly stand out from the pack.

1. QB Tom Brady

Arguably the league's standard-bearing quarterback has led all of one regular-season drive since the Patriots' Super Bowl loss to the Giants. Brady's return to vintage form is crucial for the Patriots to stage another title run. What makes his importance even greater in 2009 than in seasons prior is that New England is breaking in a new play-caller in QB coach Bill O'Brien following offensive coordinator Josh McDaniels' departure to become Denver's head coach.

2. WR Randy Moss

Moss affects defensive game plans as much as any receiver in the league. Opponents need to either roll coverage to his side, which opens opportunities for the Pats' other offensive weapons, or be victimized by Moss' otherworldly talents. His single-season record of 23 TD receptions is likely unattainable without the Pats running up the score again, but as long as he's healthy, it's tough to imagine the passing attack not remaining lethal.

3. ILB Jerod Mayo

The 2008 Defensive Rookie of the Year needs be more than the one-man wrecking crew he was in his debut campaign. He also needs to fill the LB leadership void created by the departures of former Patriots stalwarts Tedy Bruschi (retired) and Mike Vrabel (traded). Indeed, a lot is being asked of the emerging star, not the least of which is an expanded role in the blitz package after he proved capable of crashing the pocket during the latter stages of last season.

4. NT Vince Wilfork

Don't allow Wilfork's meager sack numbers to shape your perception of him. The pivot of the 3-4 "D" isn't asked to rack up gaudy stats. What is expected of Wilfork is tying up the interior O-line, controlling both "A" gaps and collapsing the pocket. He does all of them well. Despite team brass stiff-arming his request for a new contract, Wilfork will be financially rewarded by some team after the season, though he won't be happy signing a franchise tender.

5. OLT Matt Light

One of two O-line starters to be with the Patriots since 2001 — the other is ORG Stephen Neal — Light has the critical job of protecting Brady's blind side. While he's largely hailed for his consistency through the years, he doesn't possess prototypical quickness and has been victimized by some of the AFC's speedy edge rushers. What makes his task at least a little less stressful is Brady's uncanny anticipation of the blind-side pressure.

Kickoff is coming! PFW's annual Kickoff Issue goes on sale at PFWstore.com Monday evening and at newsstands and bookstores later this week. Also, be sure to buy copies of the Pro Football Weekly/Yahoo! Sports 2009 NFL preview magazine, as well as the Pro Football Weekly/Yahoo! Sports Fantasy Football Guide 2009, both of which are now available at bookstores, newsstands and retail outlets where magazines are sold. Or order your copies online at PFWStore.com.