The quarterback's league has changed a bit since Denver's defense turned Cam Newton's MVP smile to an OMG pile of Super Bowl heartbreak eight months ago.

The Panthers-Broncos rematch comes Thursday night as the NFL kicks off its 97th season with Peyton Manning retired, Tom Brady suspended, Tony Romo injured, Case Keenum standing up for Los Angeles on one side Monday night and Colin Kaepernick kneeling down against America on the other.

Meanwhile, Trevor Siemian, Jimmy Garoppolo, Dak Prescott and Carson Wentz enter Week 1 as saviors with nary a start among them. Robert Griffin III is back, having gone from a dead career in D.C. to a football town that hasn't lived in a couple of decades. And then there are guys such as Ryan Tannehill, Blaine Gabbert and even Jay Cutler who will try to live up to expectations. Again.

A league already starved for 32 starting-caliber quarterbacks got even leaner a week ago when the Vikings lost 24-year-old Teddy Bridgewater to a freak noncontact knee injury that could take longer than a full season to heal. And that, folks, is how a general manager ends up parting with a first-round draft pick and a conditional fourth-rounder for Sam Bradford, an injury-prone underachiever with career potential left. And, yes, with only five practices in purple, Bradford could wind up starting the opener against Tennessee ahead of 36-year-old journeyman Shaun Hill.

"They wouldn't give up a 1 and a 4 to have a guy sit very long," Titans coach Mike Mularkey said Wednesday when asked why he thinks Bradford will start. "And I just think he gives them a very good chance."

The Vikings, of course, weren't the only team to experience desperation at the quarterback position. The Super Bowl champions tried desperately to retain Brock Osweiller and his seven career starts as Manning's replacement. When Osweiller went to Houston as its starter, the Broncos turned to Siemian, the 250th overall pick in 2015 and part of the answer to this trivia question: Name the only defending Super Bowl champion to open the next season with a quarterback who never had thrown a pass in his career.

Newton gets the edge Thursday night. But Wade Phillips' defense still has firepower and a winning formula for defeating the Dab. In Super Bowl 50, Newton completed only 18 of 41 passes with a 55.4 passer rating, one interception and two lost fumbles.

Speaking of season-ending meltdowns, Newton isn't the only upper-echelon quarterback trying to bounce back from a bitter taste. Carson Palmer, whose Cardinals might be the best all-around team in the league, looked more like Jesse Palmer when he was slinging four interceptions for a 43.2 passer rating in last year's 49-15 NFC Championship Game loss to Carolina.

Returning from injuries are Andrew Luck, Joe Flacco and Andy Dalton, three young guys being counted on to help carry the league when some of its older quarterbacks follow Manning in retirement.

Right now, it's a stretch to say the league has a dozen elite quarterbacks. The top two from this angle are Aaron Rodgers and Ben Roethlisberger, which explains why a Packers-Steelers Super Bowl matchup seems popular and not off base.

While the nation's No. 2 television market — Los Angeles — returns to the NFL after a 22-year absence, teams in the No. 1 market — New York — spent huuuge amounts while trying to take advantage of situations in their respective divisions. The Giants added $204 million in four defensive free agents, hoping that, combined with the promotion of offensive coordinator Ben Mc- Adoo and the experience of Archie Manning's last football-playing son will be enough to beat Washington, Dallas and Philadelphia in the NFC's worst division. Meanwhile, the Jets have invested $76 million in guaranteed money on defensive linemen Sheldon Richardson, Muhammad Wilkerson and Leonard Williams in hopes that pressure finally can unseat Garropolo, Brady and the Patriots in the AFC East.

In the NFC North, the defending champion Vikings are vulnerable, to say the least, but still sport three-time rushing champion Adrian Peterson and a top-five scoring defense that returns 11 starters and more depth. The Packers are now the team to beat, while the Bears have holes despite significant upgrades on defense. And it's hard to picture Matthew Stafford and the Lions taking a big step forward without Megatron.

The Panthers were the NFC team to beat at 17-1 before losing that Super Bowl eight months ago. Then they were humiliated in San Francisco and lost All-Pro cornerback Josh Norman a week before the draft. But, hey, a new season starts Thursday.

Even Cam is smiling again.

Mark Craig covers the Vikings and the NFL for the Star Tribune. • mcraig@startribune.com