"It is with a heavy heart, but a trust in God, that we say goodbye to our beloved Dinger who lost his courageous battle with cancer," Heimerdinger's wife, Kathie, said in a statement Saturday. "Mike approached cancer with the same vigor and tenacity that he approached any football game -- to win. Even in the final minutes he never gave up -- that was our Dinger."
Heimerdinger, who died while in Mexico to receive experimental treatments, had continued to coach before he was let go by the Titans in February, along with two other assistant coaches, after offensive line coach Mike Munchak was promoted to head coach.
"He was a great coach and a tough coach," Titans running back Chris Johnson said. "I know I wouldn't have become the player I am without his confidence and the trust that he showed in me. My thoughts go out to his family."
Former Titans coach Jeff Fisher had brought Heimerdinger back in 2008 after two seasons in Denver.
"It was a tough deal and Dinger was a tough guy to the end, which is no surprise to those who knew what type of competitor he was," Fisher said in a news release. "He was a man's man. No matter how weak he looked, how weak he sounded, he never had a complaint and fought this cancer as you would only expect him to fight it."
Heimerdinger helped the late Steve McNair earn NFL co-MVP honors in 2003 and was part of three playoff teams in his first five seasons at Tennessee before taking the same job for one season with the Jets in 2005.
"The coming days will be challenging for our family and we graciously and respectfully ask that you allow us to grieve privately," Kathie Heimerdinger said.
Heimerdinger was diagnosed with cancer in November 2010 and began chemotherapy treatment five days after the diagnosis. At the time, Fisher said Heimerdinger had been very sick for three weeks.
Heimerdinger made a trip to Houston with the team for that Sunday's game and was greeted on the field before the game by his son, an intern with the Houston Texans at the time. Heimerdinger also had a daughter.
Heimerdinger was college roommates with former Broncos coach Mike Shanahan and helped coach McNair to co-MVP of the NFL with Peyton Manning in 2003.
"We lost a very special person and my best friend in Mike Heimerdinger," Shanahan, now the Redskins' coach, said in a statement. "I know the man upstairs needed a superstar so he took him earlier than we all wanted. His love for his family was unprecedented and I will forever miss him."
In Denver, Heimerdinger coached dynamic wide-receiving tandem Ed McCaffrey and Rod Smith during his first stint with the team from 1995 to 1999, helping the Broncos to back-to-back Super Bowl titles in '97 and '98.
In a statement, the Broncos said several members of their organization visited Heimerdinger last week before Sunday's game against the Titans in Nashville.
"The Broncos extend their deepest sympathies and prayers to Mike's wife, Kathie, and the rest of his family and friends during this most difficult time," the team said.
Broncos football chief John Elway, quarterback of the franchise's two Super Bowl teams, tweeted: "The world lost a great coach and a great man in the passing of Mike Heimerdinger. He was a big part of our championship years."
Heimerdinger coached Manning in a couple of Pro Bowls, and they played golf together in the offseason, and Manning noted Saturday that Heimerdinger was close with Kerry Collins, now with the Colts, and a couple of other players in Indianapolis.
"So it's sad around here today as well," Manning said in a statement. "He was a man's man. I appreciated his friendship. I am sorry and sad about his passing. He will be missed, and my prayers are with his family."
Collins called Heimerdinger a great friend who will be sorely missed.
"Those of us that were fortunate enough to know Dinger will always remember his passion for life and love of the game," Collins said in a statement.
Jets receiver Derrick Mason sent his prayers to the Heimerdinger family on Twitter. Heimerdinger was Tennessee's offensive coordinator when Mason got the chance to play receiver in the NFL when he had been working just as a returner.
"Dinger gave me a opportunity and I will forever thank him for that! Great teacher!!" Mason wrote.
"You don't expect these types of things to happen and they shouldn't happen," Titans tackle Michael Roos said. "I felt confident that he was going to beat this after seeing his resolve last season in dealing with it. He was such a competitor and a fighter -- the things that made him such a good coach were also the traits that I thought would lead him to beat the cancer."
Heimerdinger was born in Dekalb, Ill., and was a receiver and center fielder at Eastern Illinois, where he received a degree in history.
He spent four years as a high school coach in McHenry, Ill., and then was a coach at the University of Florida, the Air Force Academy, North Texas State, Cal State-Fullerton, Rice and Duke.
"He loved his family, he loved this game and all that came with it," Fisher said. "We've lost a great one."
Information from The Associated Press was used in this report.