Super Bowl threats or title pretenders?

The Vikings and Buccaneers, who play each other, and the Jaguars and Jets are four teams supposedly ready to chase for a championship. Beginning Sunday, fans find out if they are for real.The biggest test comes in the Metrodome, where the two teams expected to challenge Green Bay's dominance of the NFC Central meet in the opener. The Bucs turned things around with an impressive defense last year, while the Vikes might have the league's most potent attack.

"You don't want to start thinking like this game has end-of-the-season implications because it only counts for one," Vikings coach Dennis Green cautioned. "If you allow it to count for more than one, then you're hurting yourself, no matter what happens."

Still, it's a barometer for both squads.

"It's crucial to try to win this one because you figure Minnesota is going to be a team that you're up there competing with," Bucs coach Tony Dungy said. "That's the way we're approaching it."

So are the Vikings.

"It's very important," said cornerback Corey Fuller. "It's to set the tempo at the start of the season and what type of team you're going to be."

The Jets can do the same thing, making a major statement with a victory at San Francisco. Of course, with Jerry Rice returning to the 49ers, even staying close might be an achievement for New York, the only team not to win a division title since the 1970 merger.

"This is the first game and obviously we want to come out and show we are for real and build on last year," Jets receiver Wayne Chrebet said, referring to the Jets' turnaround from 1-15 to 9-7 under coach Bill Parcells. "It just happens we're playing a team the caliber of the 49ers on national television, with Jerry Rice making his comeback. It's a natural thing for the game to get the attention. We just happen to be a part of it."

The Jaguars think they could be part of something special, too. They've made the playoffs the last two years and are primed to challenge Pittsburgh in the AFC Central. They get started at Chicago.

"While you look at it as a compliment, that's exactly where it stays," coach Tom Coughlin said of Jacksonville being rated a contender. "A lot of that is well-scheduled and well-planned hype during two a days and during training camp. Now the reality of the season gets into play.

"There are a minimum of 16 games to go. One game at a time would be the only way that this and every other team in the NFL can be evaluated."

Elsewhere, John Elway, returns for his 16th and almost certainly last season, and he does it as a champion for the first time. Denver is at home Monday night against New England.

Last year's co-MVPs, Brett Favre and Barry Sanders, meet in Green Bay as the Packers play Detroit. Top draft picks Peyton Manning and Ryan Leaf make their pro debuts at quarterback. Manning is at home in Indianapolis to play Miami, while Leaf also is at home, in San Diego vs. Buffalo.

Also, it's Atlanta at Carolina, New Orleans at St. Louis, Pittsburgh at Baltimore, Seattle at Philadelphia, Tennessee at Cincinnati, Washington at the New York Giants, Arizona at Dallas and Oakland at Kansas City.

The Ravens unveil their new $223 million stadium in what could be an intense game.

"They're coming off a 4-0 preseason, it's the first regular-season game in a new stadium and we're the Pittsburgh Steelers," Steelers coach Bill Cowher said. "We're aware of the kind of arena we're going to step into Sunday afternoon."

Baltimore looked great in the exhibition season, going 4-0 and outscoring opponents 89-26. They were potent with the ball and dominant without it.

"The preseason means absolutely nothing," Ravens defensive tackle Tony Siragusa said. "It's a whole new ball game."