Five things you need to know about the Vikings:

1. The Vikings might as well have canceled training camp: Half of their offensive starters missed substantial practice time, from quarterback Brett Favre to tailback Adrian Peterson to receivers Sidney Rice and Percy Harvin to center John Sullivan. That put a premium on the three or so weeks the team spent practicing at their permanent facility between the end of camp and their Sept. 9 season opener at New Orleans. That was their only time to come together as a group and figure out what kind of offense they want to be.

2. It's going to be tough to replicate last season's passing numbers: Rice won't return until midseason following hip surgery and Harvin's recurring migraines make him a question mark on a daily basis. That leaves the Vikings with one established big-play receiver (Bernard Berrian) and two possession receivers (Greg Lewis and Greg Camarillo). It's probably safe to assume Favre will lean heavily on tight end Visanthe Shiancoe and will also use Peterson out of the backfield as much as possible. Stranger things have happened, but even Favre himself spent most of the summer trying to temper expectations for the passing portion of this offense.

3. Peterson has more pressure on him than ever: The passing game rescued what became an inexplicably average running game last season, but the Vikings can't count on a repeat in 2010. Peterson skipped the team's offseason program, passed on minicamp and missed a week of training camp because of a strained hamstring. That wasn't a good start, but he will get every opportunity to carry as much of the total offensive load that he can. The departure of backup Chester Taylor offers the opportunity to expand Peterson's role in third-down situations, but the Vikings aren't yet confident in his blocking abilities.

4. The early schedule is brutal: In the first half of the season, the Vikings will play at the Saints, Jets, Packers and Patriots. They'll also host the Cowboys at the Metrodome. All five of those opponents made the playoffs last season, and you could make a reasonable argument for all five as Super Bowl contenders. That's a tough stretch no matter what condition the team is in. For one that had a summer as traumatic as the Vikings, it could be season-defining. If they enter the second half of the season more than a game above .500, they should be thrilled.

5. Middle linebacker E.J. Henderson is a miraculous story: Henderson suffered a fractured femur last December in a horrific injury that seemed to threaten his career. At best, doctors thought it would take him a year to recover, putting him on a timetable to resume play in 2011. But with a permanent titanium rod providing support, Henderson cut that timetable in half and by all appearances has recaptured his starting job. Time will tell how he holds up over the course of the season, but simply putting on a helmet this summer was a wondrous accomplishment.

-- Kevin Seifert, ESPN.com