Some players would be hard to live without

One of the best commercials out there -- gotta give it up to the competition -- is the NFL Network ad featuring San Diego Chargers Philip Rivers, Shawne Merriman, Antonio Gates and Lorenzo Neal.

If you haven't seen it, it goes something like this: A couple of guys are talking football at the water cooler when one comments that if you were to take LaDainian Tomlinson out of San Diego's lineup, the Chargers would be done. Suddenly the offended Chargers appear to correct the know-it-all who, in the words of Rich Eisen, was guilty of exaggerating his football knowledge, Merriman warning the fan that it isn't wise to offend "Mr. Gates." It's a great spot. Very poignant.

What the embarrassed fan was trying to say was that Tomlinson, in a word, is indispensable. Perhaps. And then again, perhaps not. Fortunately for the Chargers, L.T. has missed only one game in his career, and while one would assume San Diego's offense would sputter without its all-time great running back, backup Michael Turner has looked pretty good when he's carried the ball.

You hear that word being thrown around a lot with regard to elite players: indispensable. By definition it means "absolutely necessary, essential, or requisite." In football terms, it's an irreplaceable player without whom his team would not be successful. It's the guy who has to not only play but to play well for his team to have a chance to win.

It's also a concept that's contradictory to the very culture of the sport.

Football is the ultimate team sport. Sure, teams have their star players, but what they all have to have to be successful is good depth. Good teams aren't built around individuals and are able to withstand losses either through injury or free agency.

A team such as New England, for example, seems to march on no matter whom they lose. It's as if Patriots players are merely interchangeable parts. Teams pride themselves on being able to press on no matter who goes down. It's not like they're going to cancel the games or anything.

You might have thought the Chiefs were cooked when Trent Green suffered his concussion Week 1, but K.C. managed to win two games with Damon Huard, a guy who hadn't completed a pass in five years. And as for those Chargers, who'd have thought they'd be one of the league's dominant teams after letting Pro Bowl quarterback Drew Brees go to free agency? The Eagles haven't had a problem replacing Terrell Owens' production. The Colts are undefeated and rolling along with Edgerrin James gone to Arizona. And so on and so on.

So, really, who is indispensable? Is anyone?

Well, you certainly could make an argument for Carolina wide receiver Steve Smith. His value to the Panthers is obvious. Carolina couldn't win without him (0-2) and the Panthers are 4-1 with him, with the only loss coming this past Sunday. That Smith's return coincided with Carolina's winning streak has people talking about Smith as a leading MVP candidate. On the other hand, would the Panthers be on such a roll if defensive end Julius Peppers weren't on such a tear (NFL-high eight sacks)?

That got us to thinking here at ESPN.com: Which players around the league are closest to indispensable?

Let me tell you, even with the help of Scouts, Inc.'s Jeremy Green, personnel people, coaches and players around the league, it wasn't easy coming up with the All-Indispensable Team. Honestly, most of the starting quarterbacks in the league qualify as indispensable. But we could choose only one, and it's Peyton Manning, not because he's better than, say, Tom Brady or Donovan McNabb, but because Indianapolis does not win when Manning does not play well.

We mentioned L.T., a legitimate MVP candidate just about every year. Steven Jackson is carrying an L.T.-type load for St. Louis. We could literally dub a half-dozen running backs as indispensable. But when it came down to it, we went with two tailbacks, both coincidentally from the NFC East, whose offenses would completely bog down without them in the lineup. Tiki Barber and Brian Westbrook are just that good.

The strength of the lines is the group. But for the purposes of this team, we had to come up with five individuals, so we selected the consensus best players at each position up front. So excuse us if it just looks like an All-Pro team.

You might notice some big names missing from the defense, like reigning Defensive Player of the Year Brian Urlacher and Baltimore's Ray Lewis. Neither the Bears nor Ravens, nor any team for that matter, can afford to lose its Mike linebacker, it's quarterback on defense. But what it came down to with these two All-Pros is the fact that they play for star-studded defenses, and at times they aren't the best players in their units.

And it certainly wasn't easy assembling a secondary without the likes of Rodney Harrison, Mike Brown (the Bears are about to see, again, what he means to that defense), Bob Sanders, Brian Dawkins, Roy Williams … you get the idea. But it would have been even more of a mistake, in ours and our consultants' views, to exclude the two most complete safeties in the game today: Troy Polamalu and Ed Reed.

Tomorrow, if given the assignment again, we could assemble an entirely different list. There are that many players whom some teams can't imagine living without.

Michael Smith is a senior writer for ESPN.com.