The NFL is a league full of parity. With teams' talent levels not varying too much, unheralded squads are breaking into the postseason each year.
It also means that continued success is hard to sustain. Getting back to the playoffs each year is a struggle, no matter how talented a team is.
For many of last season's playoff teams, their postseason appearances might have been the peak of their success. The team may have had a fluke season or lost key members since its run.
And with other hungry teams vying for a spot, repeating is a daunting task. Squads like the Pittsburgh Steelers and Atlanta Falcons have to be chomping at the bit to return to the playoffs.
With that said, here are five teams, with some honorable mentions, that will have trouble getting back to the postseason.
San Diego Chargers: Although they are perennial contenders every season, the Chargers could be without two key weapons if Vincent Jackson and Marcus McNeill continue their holdouts into the season. Plus, the team must start anew with its ground game as it breaks in Ryan Mathews. A relatively weak AFC West makes a chance at a division title much easier, however.
New York Jets: Yes, the Jets are supremely talented. But with so many egos and characters on the team, will they be able to put it all together? The year could be a huge disappointment if this team doesn't gel. The Jets have swagger, but they need to put it together on the field. Plus, the Darrelle Revis situation doesn't look like it will be over any time soon.
New Orleans Saints: Every Super Bowl team faces ridiculous expectations after its championship. Many succumb and fail to make the playoffs, and those who do make it rarely have success. Five defending champs in the last 11 years didn't make the postseason the next year, and only three won a playoff game. Although the Saints are stacked, returning to the postseason might not be so easy.
With Brett Favre supposedly gone for good, this team looks markedly different than last year's NFC Championship team.
He might just be one player, but Favre gave the Vikings the weapon they needed to succeed in the NFC. With the task passed down to Tarvaris Jackson or Sage Rosenfels, the future is uncertain.
Although Jackson has supposedly improved since Favre joined the Vikings, it's hard to trust such a young, unproven quarterback to lead a team.
If he can't be effective at quarterback, the Vikings will become predictable on offense. Defenses will cram the box as they try to stop Adrian Peterson. If that happens, the offense will be one-dimensional and futile, no matter how talented Peterson is.
If Jackson truly has developed, the team has a good chance to return. But if he hasn't, it's tough to say that it will make the playoffs.
With that said, Vikings' fans have to be crossing their fingers, hoping Favre decides to return for one more season.
The Patriots didn't look like the team of old all last season, and no game showed that more than the 33-14 drubbing put on them by the Baltimore Ravens in the playoffs.
Since losing to the New York Giants in Super Bowl XLII, New England has struggled to retain success as the team ages.
The problems begin at wide receiver. Wes Welker will undoubtedly be slowed by the ACL injury he sustained late last season. Although Julian Edelman is a viable backup, he doesn't provide nearly the same ability of Welker.
Plus, Randy Moss is aging quickly and has definitely lost a step in the last few years.
On top of that, Logan Mankins is still holding out, while Tom Brady is also unhappy about his contract. Don't expect the Brady contract talks to affect the quarterback too much, however.
The defense also isn't what it used to be. Jerod Mayo and Vince Wilfork are studs, but the rest of the defense is mediocre.
Plus, hungry AFC East competitors are vying for the spotlight. The New York Jets and Miami Dolphins both will try to have breakout seasons this year. With that said, a changing of the guard in the AFC East isn't out of the question.
People may be high on the Bengals for bolstering their passing attack through the addition of Terrell Owens, but will that really be enough to improve the offense?
In 2009 Carson Palmer looked like a very different quarterback than the gunslinger we've become accustomed to. It could be argued that Palmer was jumpy in the pocket because of the lack of talent at receiver and the lack of pass protection.
He'll have to prove that 2009 was a fluke. But with two aging receivers in Chad Ochocinco and Owens, how possible is it?
If the passing attack can't get off the ground, the Bengals will resort to their smash-mouth running style with Cedric Benson. The plan failed miserably at the end of last season as teams picked up on Cincinnati's predictable game plan.
Plus, the schedule is brutal, and Cincinnati must deal with two teams that weren't happy about its AFC North title last season. The Ravens and Steelers both will come at Cincinnati with fervor because of what happened last season.
Success hinges on Palmer and the passing attack. If they can't pull through, it could be a disappointing season in Cincinnati.
The Eagles are in rebuilding mode. For most teams that would mean a season well under .500. For the Eagles, failing to make the playoffs would be a disappointment.
Gone are Philly icons Donovan McNabb and Brian Westbrook. The two are replaced by Kevin Kolb and LeSean McCoy, who are both unproven.
Eagles' fans have to hope that Kolb can be the next Aaron Rodgers, a guy who waited in the wings behind a veteran quarterback and seamlessly transitioned into the starting role.
But it's hard to put so much hope in Kolb, who has great accuracy but not great arm strength. His development is the key to the Eagles' success.
With that said, look for the Eagles to focus on the ground game as they give McCoy tons of carries as Kolb develops.
Philadelphia must also find a way to replace Sheldon Brown at corner. The former Eagle was always a sold No. 2 corner in Philly, and it's unclear who will replace him.
In the end, Kolb's progression is the key to the season. With a new quarterback at the helm, it will be tough for the Eagles to clinch a playoff birth.
Like Philadelphia, Arizona must break in a new quarterback in 2010.
But replacing Kurt Warner appears to be a more daunting task than replacing McNabb is. Warner was the heart of the Cardinal franchise and the biggest reason for its playoff success the last few seasons.
Matt Leinart takes the helm now and has never looked comfortable as the starter in Arizona. He doesn't have the arm strength and quick decision-making Warner had, which is what made the offense so succesful.
Anquan Boldin is also gone, giving Leinart fewer weapons to work with. Arizona is hoping Steve Breaston or Early Doucet can step in, but neither is as talented as Boldin is.
Plus, key defenders Antrel Rolle and Karlos Dansby are gone, severely hampering the defense. Arizona is hoping former Jet Kerry Rhodes can fill in for Rolle, but the defense overall is pretty lacking.
One thing going for the Cardinals is the fact they play in the NFC West, arguably the NFL's worst division. Arizona can win four easy games against Seattle and St. Louis. It looks like San Francisco is the new top dog in the division now, however.
Cardinals' fans have been spoiled by Warner's amazing play the last few seasons. With Leinart at the helm, that magic can turn to mediocrity if the new quarterback hasn't developed.