PITTSBURGH -- Defensive lineman Cameron Heyward and the Pittsburgh Steelers agreed to a three-year, $45 million deal that includes $29 million in new money and $16 million fully guaranteed, sources told ESPN's Jeremy Fowler, giving Heyward the security he needed to become a coveted "one-helmet guy" and eventually retire a Steeler.

"There's certain guys that are one-helmet guys, and I want to be one of those one-helmet guys," Heyward, 35, said in June amid contract negotiations. "And there's a hunger and desire there, but that doesn't mean just hanging it up and calling it a career. To me, I think I got more bullets to fire, and I'm excited to do that."

The Steelers announced a three-year deal with Heyward on Tuesday afternoon but did not disclose terms.

Coming off a groin injury that shortened his 2023 season, Heyward was set to enter the final year of his previous deal but is now under contract through 2026 with a deal that's believed to be the largest contract for a defensive player over the age of 35 in NFL history. Heyward's deal, which had a deadline of the season opener because the Steelers don't negotiate contracts in-season, also included a nearly $15 million signing bonus.

The team's first-round pick in 2011, Heyward was also recently selected to be a team captain for the 10th consecutive season and was named the NFL's 2023 Walter Payton Man of the Year.

In his 13-year career, Heyward has 80.5 sacks, 2 interceptions and 8 forced fumbles en route to six Pro Bowl selections.

Heyward skipped several OTA practices for the first time in his career during the offseason amid negotiations, but he returned for several practices and reported for minicamp.

"Everybody's entitled to their opinion, but I want to make your opinion wrong, and I think I just look forward to playing good football," Heyward said Monday when asked about being motivated by his doubters. "I understand this is a fragile game and you are not promised tomorrow, but I'm trying to maximize everything out of it and I'm going to approach it that way. I'm not going to run from it. I'm just going to run straight into it."