The Packers and their fans know how to celebrate at Lambeau Field, and they long to celebrate another Super Bowl title after the 2011 season. (Scott Boehm/GETTY IMAGES)

No matter the outcome of the NFL season opener at Lambeau Field on Thursday night, the champion Green Bay Packers are about to discover what their predecessors, the New Orleans Saints, learned last season: Defending a title presents its own set of challenges more daunting, in so many ways, than securing a single Super Bowl triumph.

But as one of the most unusual NFL offseasons finally gives way to the post-lockout regular season, some of this year’s circumstances might actually work in the Packers’ favor as they attempt to become the sport’s first repeat champions since the New England Patriots in the 2004 season.

“I think if anything, it may help them,” said Jimmy Johnson, the former coach of the Dallas Cowboys and Miami Dolphins. “I think there’s a vast difference between the real good teams and the bad teams this year. Whereas in previous years, the bad teams, with all the offseason work and free agency and being able to draft some players and get them ready for the season and play some young players, there were always upsets early in the year. I think the veteran teams are going to dominate early in the season this year.”

The NFL’s recent history says the Packers face an uphill climb, which they begin against the Saints on Thursday night. No NFC team has won consecutive Super Bowls since the Cowboys in 1992 and 1993. Those Cowboys and two AFC teams, the 1997 and ’98 Denver Broncos and the Patriots in the 2003 and ’04 seasons, are the only NFL clubs to repeat as Super Bowl champions in the past two decades.

Over the last 10 seasons, the NFC has been represented in the Super Bowl by 10 teams. Simply reaching the playoffs in consecutive seasons is difficult enough. There have been at least five new playoff teams each season over the past 15 years.

“We’re asked that question [about repeating] every year after someone wins because it’s hard then to imagine that team not being the best team in the league the following year,” former Cowboys quarterback Troy Aikman, now an NFL analyst for Fox, said in a conference call with reporters last week. “It’s hard to imagine the Green Bay Packers not being the best team in the league, especially considering all the injuries that they had last year. But it’s just hard to do. It’s hard to repeat a playoff year. . . . It’s just a different league now than what it once was.”

It’s not only the way that pro football now operates, with a salary cap forcing tough decisions on owners and players moving from team to team in free agency, that works against a defending Super Bowl champion. It’s also human nature, Johnson said.

“Everybody says, ‘What about me? Give me more money. Give me more accolades. Give me more publicity. Give me more of everything,’ ” Johnson said. “And that hurts the team concept.”

But many predict that teams with new coaches and young quarterbacks will struggle after the sport’s 4-1 / 2-month offseason shutdown. If the league’s “any given Sunday” unpredictability is disrupted, that could help diminish top-notch competition for teams with more stability — such as the Packers, who won the Super Bowl last season despite having 16 players on the injured reserve list.

“I got to know that team awfully well last year,” Aikman said. “And with [Coach Mike] McCarthy and [quarterback] Aaron Rodgers and the rest of those guys, I don’t think they’re going to be affected negatively by the lockout. I think they’ll be just fine.”

Some have speculated that the Philadelphia Eagles might be the team to beat in the NFC, after an ambitious post-lockout shopping spree that led their new backup quarterback, Vince Young, to dub them a “dream team.” But their general manager, Howie Roseman, wasn’t taking that view as he sat beneath a tent next to a practice field during training camp.

“We’re chasing,” Roseman said. “We’re chasing the Green Bay Packers, the Super Bowl champions last year. The New Orleans Saints won the Super Bowl. . . .We know there are no guarantees. We know we’ve got a lot of work to do.”

It has been a tumultuous seven months for those in the sport since the Packers beat the Pittsburgh Steelers in Super Bowl XLV. The focus officially returns to a season opener Thursday that provides a first glimpse at how the disrupted offseason will affect the level of play.

Virtually everyone in the NFL seems eager to move on. Patriots Coach Bill Belichick said at a news conference late in the preseason that dealing with the lack of the normal offseason activities was “kind of old news.”

Belichick said his team, at that point, hadn’t made its usual progress, but added: “I think the first few days [after the lockout], that was a transition. That was different. . . . [But] this year is no different than any other year in terms of making the final roster cuts, dealing with the opener, trying to figure out what your roster is, looking at what other teams are doing. So that part of it is really pretty much the same.”