NFL Media Insider Ian Rapoport reported that Mathis can earn up to $4 million with incentives tied to playing time.
The 33-year-old confirmed Rapoport's report that he turned down a $5.5 million offer from another team because of his desire to play for a contender. The Philadelphia Eagles cut Mathis this offseason when he was scheduled to make $5.5 million.
"But I also turned down an offer equal to what I would have made in Philly," Mathis said. "It was a decision to be on a team I thought had the best chance to make a run. And it's not all about the money. You can't put a price on peace of mind."
In Denver, Mathis will slide into a starting spot, adding a veteran presence to a line that started three linemen without a snap of NFL experience in their most recent preseason game.
Mathis said he's willing to become a teacher for the bevy of younger players.
"I think I've learned a lot, I think I have a lot to share with these guys as well as the technical aspects of the game," he said. "And then ultimately leading by doing the right thing. Taking care of my body. Playing as hard as I can play. Making the decisions in life that ultimately make me a better ballplayer."