ENGLEWOOD, Colo. -- The Denver Broncos rookies reported for training camp on Thursday and the veterans report on Tuesday at the Centura Health Training Center. Here is a look at some of the have-to-know storylines:

Biggest question: Can Sean Payton really fix this offense?

Look, it’s a hefty to-do list for anybody, but now that he is one of the highest-paid coaches in the league, that list is squarely on Payton’s desk. The Broncos haven’t been to the playoffs since winning Super Bowl 50 to close out the 2015 season, they haven’t scored more than 21 points a game since that year and quarterback Russell Wilson is coming off his worst career year -- 16 touchdown passes and a league- and career-most 55 times sacked.

The Broncos spent big in free agency in the offensive line -- almost $140 million in contracts to tackle Mike McGlinchey and guard Ben Powers and Payton has repeatedly said he has “a vision’’ of how to fit Wilson and the other players into an offense that has been the team’s biggest problem since Peyton Manning retired.

The player with the most to prove: It’s Wilson, by a Rocky Mountain mile

The Broncos pushed all the chips in when they traded five draft picks and three starters to acquire Wilson before the 2022 season.

They then signed him to a $245 million extension before he had even taken a snap. One dismal season on offense (a league-worst 16.9 points per game) and one fired head coach in Nathaniel Hackett later, the Broncos are in don’t call-it-a-rebuild rebuild mode. Wilson’s contract makes it financially painful to move on any time before the end of the ’24 season at the earliest, so this has to work.

And Wilson has to do his part.

Wilson didn’t get much help in pass protection or playcalling last year in a mismatched offensive plan, but he had plenty to repair when this offseason began. His footwork and decision-making eroded as things went bad with plenty of those 55 sacks as his responsibility.

The other player with the most to prove: Randy Gregory, OLB

Gregory, who has never played a full season in the NFL, either due to injuries or suspensions, was signed to a five-year, $70 million deal a year ago. And then a Week 4 knee injury derailed his season -- he played in six games -- and an on-field meltdown (an unsportsmanlike conduct penalty as well as a roughing the quarterback penalty) before he was benched in the Christmas Day loss in Los Angeles took away much of the momentum after his return.

Gregory was impactful when he played, the Broncos simply didn’t get enough of it in their defense. His 189 snaps on defense amounted to the second-lowest total in a season in a career that's never seen him play more than 14 games in a season.

Training camp is a success if ... The Broncos can simply escape even remotely healthier than last year

Hackett tried to dial things back as far as things could be dialed back -- the starters didn’t play any in the preseason games and practices were designed, Hackett said, with a safety-first mindset.

But it didn’t matter as wide receiver Tim Patrick and running back Damarea Crockett each tore an ACL in the first week of camp and the injuries never stopped. The Broncos eventually finished the season with two dozen players on injured reserve, including Patrick, left tackle Garett Bolles, running back Javonte Williams, wide receiver KJ Hamler, guard Dalton Risner and defensive end Dre’Mont Jones.

Payton says he plans on upping the tempo and physicality of practices, but this is not a deep roster -- they traded six first- or second-round picks to get Wilson and Payton -- so they’ll need some good fortune.

Fiercest fantasy-relevant battle: Not really a “battle,’’ but Williams’ recovery from his torn ACL

Williams, who rushed for 903 yards as a rookie in 2021 and had 204 yards rushing in 47 carries last season before his Week 4 injury, suffered a torn ACL and LCL in his right knee as well as some other damage to the knee in the Broncos' Oct. 2 loss to the Las Vegas Raiders.

He has been a near-constant presence at the Broncos’ complex throughout the offseason and participated in OTAs as well as minicamp on a limited basis. He is expected to participate at least some when camp opens and gradually increase his workload if things go well.

When asked earlier this month if he believed he would be ready by Week 1, he said “That’s the plan. I feel like I’m ready to go.’’

The Broncos didn't draft a running back this year but signed Samaje Perine in free agency, who hasn’t had more than 95 carries in a season since he was a rookie in 2017.