The last words coming from the mouth of Eagles coach Andy Reid were the most realistic.

"The key to this whole thing is staying healthy," Reid said.

How true. No matter how meticulously a team works a roster and plots a season, luck is becoming more and more important in winning a Super Bowl. Sure, you need talent and great coaching, but teams that stay healthy and get on a roll down the stretch win Super Bowls.

	Andy Reid, right, has taken Philadelphia to the playoffs the past two seasons.

While recently riding in a car with Chiefs coach Dick Vermeil, Reid pointed out that schedules also play a major part. His studies show that the last half dozen or so Super Bowl winners had less than .500 records against winning teams but they get on a roll against the easier schedules. The Rams, Ravens and Patriots got hot and healthy at the right times and claimed their rings.

Because of the salary cap, it's lonely at the top. The Eagles are finding that out. Their playoff string should reach three this season. They are clearly the best team in the NFC East. Quarterback Donovan McNabb continues to evolve into one of the game's best.

Yet, the Eagles have left themselves open for criticism by hitting the free-agent market for only two players this offseason -- safety Blaine Bishop and linebacker Shawn Barber. Cost: $3.16 million. They cleared out more than that by letting middle linebacker Jeremiah Trotter go to the Washington Redskins.

Did the Eagles do enough?

"I feel good about our team," Reid said. "I told everybody going into free agency that we weren't going to make a lot of news. We feel that you don't win championships through free agency. You win them by developing your own players. We've got a lot of good young players. We feel good about ours."

The Eagles top the salary-cap sheet by having $9.9 million of available room. That's a staggering amount these days. Reid was going to be a cautious shopper anyways. Though there is a little bit of age on the defense, the Eagles are a team hitting its prime at the right time.

Of the four NFL finalists last year, though, they were the least active. The Steelers locked up their team for the next four years by spending $63 million of signing bonuses on 22 players. The Patriots continued to spread their resources on depth and brought in their usual list of a dozen role-playing veterans. The Rams believe they didn't retreat by replacing middle linebacker London Fletcher with Jamie Duncan and wideout Az-Zahir Hakim with Terrence Wilkins.

Dollars can't be converted into victories, so good teams -- and the Eagles are a good team -- can go as long as their talent and health carry them. Where the Eagles leave themselves open for criticism is having so much cap room available and not bringing in more veterans from the outside.

A year ago, Reid gambled and won by deciding to go with young receivers. He cut veterans Charles Johnson and Torance Small and went with four young pups -- James Thrash, Todd Pinkston, Freddie Mitchell and Na Brown. Though Trash (63 catches) was the only wide receiver who caught more than 50 passes, McNabb ran around and made enough plays to get the Eagles to the NFC championship game against the Rams.

The Rams won that contest, but it's pretty hard to look back and say Reid was wrong. The Rams were the better team. They had been in the playoffs a year longer than the Eagles. Their offense was the best and they made the major changes on defense that got them back to the Super Bowl.

Like last year, Reid is gambling on his own players. If Barry Gardner can make Eagles fans forget Trotter, the defense won't be negatively affected. If Hank Fraley holds up as the fulltime center for the departed Bubba Miller, then the offensive line is in good shape.

Perhaps the most interesting decision is at running back, where the Eagles lost backup Correll Buckhalter for the season with a knee injury. Reid groomed third-round choice Brian Westbrook and Rod "He Hate Me" Smart during the past two months.

	"	I feel good about our team. I told everybody going into free agency that we weren't going to make a lot of news. We feel that you don't win championship through free agency. You win them by developing your own players. We've got a lot of good young players. We feel good about ours. "
		— Andy Reid, Eagles head coach

"Rod has changed his name to 'He Love Me,' " Reid joked. "We are going into the fourth year with this offense, so there is a volume of plays to be learned. We really wanted the young guys to get reps and get a good look at them."

If former Packer Dorsey Levens is still available before the opening of camp, Reid might sign him for insurance against injury. "I'm not closing my eyes on everything," Reid said. Because the system in Philadelphia is the same as it is in Green Bay, Levens can sign and fit into the offense as a backup without problem.

"My biggest concern is if I can spot Duce Staley," Reid said. "Sometimes, I wear him out. In our first year, he was responsible for 70 percent of our offense. He's catches the ball so well and he runs so well, we want to make a point of not giving him too much work."

It was interesting last week that the Eagles made a move for middle linebacker Hardy Nickerson but lost him to the Packers. Nickerson hinted that the Packers fit him better because he felt they were better suited to go to the Super Bowl. But the Eagles weren't looking for Nickerson to be a starter. The Packers were.

"I brought Hardy in because what I wanted him for was competition," Reid said. "It's great to have a veteran for backup support. I have a bunch of young guys. If we didn't get him, then we were still fine."

With Trotter gone, outside linebacker Carlos Emmons goes from being a two-down player to three downs. Gardner has to anchor the middle of the defense on first and second downs. An injury to two could cause things to crash, though. Same thing on the offensive line if Fraley gets hurt at center.

"Hank has really played well, and we also have Doug Brzezinski working in there, too," Reid said. "We also like Scott Peters (a fourth-round choice), who we got out of Arizona State."

Reid has answers because he believes in his team. He should. Because of their talent and way that they manage the cap, this fall won't be the Eagles' only shot at the Super Bowl.

And ultimately, the Super Bowl for the Eagles will be determined by the play of McNabb. Last year, he made significant advances in being able to make plays against the blitz, something many West Coast quarterbacks don't pick up until their fourth year or later.

"We have pinpointed through the history of this offense that you see a great jump from the first year to the second and the second to the third," Reid said. "Donovan's work ethic elevated his play in the third year. He gives it so much time and effort and was ahead of schedule. In that fourth year, you see quarterbacks becoming more accurate not just on the straight dropback throwing game but when he has to throw offbalance."

This could be the Eagles' year. Still, it's too bad that more of that $9.9 million of cap room couldn't have been used to at least improve their depth. If the Eagles find their depth a player or two short and don't get a ring, that would be enough to make them sick.

The key is staying healthy.

John Clayton is a senior writer for ESPN.com.