SANTA CLARA, Calif. – Super Bowl 50 has some of the more resilient coaches the NFL has ever seen.

We'll start with Denver Broncos coach Gary Kubiak. Twenty-seven months ago, Kubiak was coaching the Houston Texans when he suffered a mini-stroke and collapsed while jogging off the field at halftime of a nationally televised game.

"I don't think it changed me as a person," Kubiak said Tuesday. "I think after going through that and talking to a lot of doctors there in Houston, I think it made me change a little bit as a coach and how I go about things.

"I know exactly why it happened. I know what I was doing and what I was putting myself through trying to do too much. I still love the work, so I'm going to be up early in the morning working the hours, but I've also tried to go about it a different way. Not try to take on everything myself and understand I've got good people with me."

Kubiak said it was only a minor stroke and that he never thought it would end his coaching career. Just like getting fired in Houston after a 2-11 start in 2013 didn't cause him to think his 61-64 overall mark would prevent him from getting another head coaching job.

"I was very fortunate," said Kubiak, referring to the path that took him to Baltimore as an assistant and then to Denver this season when General Manager John Elway turned to his former backup quarterback to instill more toughness into a team that played in the Super Bowl only two years ago.

Carolina Panthers head coach Ron Rivera.

Kubiak managed the offense around Peyton Manning's injuries. But defensively, the credit goes to 68-year-old coordinator Wade Phillips, who was out of football a year ago. It was Phillips who instilled instant success in increased toughness to that side of the ball, much like he did under Kubiak in Houston.

Then there's Panthers coach Ron Rivera, who could produce the first 18-1 Super Bowl champion since the 1985 Bears, a team for which Rivera played linebacker.

It took eight head coaching interviews before Rivera finally landed the Panthers job. Then he appeared on the verge of losing that job numerous times, including Nov. 30, 2014, when he visited TCF Bank Stadium and left with a 3-8-1 record after his Panthers gave up two blocked punts for touchdowns in a 31-13 loss to the Vikings.

Kubiak, Phillips and Rivera are testaments to never giving up. But the most determined coach in the game is Panthers special teams coordinator Bruce DeHaven.

In May of last year, DeHaven was told he had terminal prostate cancer. He would have three to five years to live.

He decided to keep coaching even though the 67-year-old lives in Buffalo in the offseason. DeHaven received treatments in Buffalo throughout the season but missed only one meeting all year because of his condition.

Players say they don't even notice DeHaven's illness. Meanwhile, DeHaven is trying to get reporters to stop making him a story line this week. It's not working.

"I feel good," he said. "I don't really want to talk about it much and a lot of that is because my kids just don't need to hear me talk about all of this. Toby is a freshman in college and Annie is a sophomore in high school. They don't need to hear their dad talking about being sick. They see me and I look good so that's what they need to see."

He even joked about how his decision to keep coaching turned out.

"Well," he said, "it seems like a pretty good decision now, doesn't it? That's the thing about football. You never know."