Jack Del Rio has been here before. (Jack Dempsey / AP)

The Denver Broncos will turn to an assistant with NFL head-coaching experience to help them get through the next weeks without John Fox, who is expected to have surgery to replace a faulty heart valve this week.

Broncos defensive coordinator Jack Del Rio, head coach of the Jacksonville Jaguars for nine years, will step up while Fox is recovering from aortic valve replacement surgery. Fox, 58, had planned to have the surgery after the season and was golfing Saturday afternoon in Charlotte, N.C., when he felt “light-headed,” according to the team. Fox was in North Carolina to see his cardiologist and had been warned of symptoms to watch for. It was determined that the procedure could not wait until after the season.

“I sincerely appreciate all of the support from friends, Denver Broncos fans and so many around the league today,” Fox said in a statement released by the team. “Although I am disappointed I must take some time away from the team to attend to this pre-existing health condition, I understand that it’s the right thing to do. I have great confidence in our coaches and players, who are fully committed to our goals.

“I look forward to returning to coaching as soon as possible.”

The Broncos are 7-1 and next face the San Diego Chargers on Nov. 10. The team, with Peyton Manning and Super Bowl aspirations, face the meaty part of their schedule going forward, with two games against the Chiefs and one against the New England Patriots after the Chargers game. Losing him was a shock for players.

“I read about it online, and I was surprised,” wide receiver Eric Decker told the Denver Post. “I didn’t know he had prior conditions. It seemed like he was in good health. He always seemed like he was in good spirits. Never seemed like he had an episode. It was hard. He’s not only the leader of our team, he really is like a father figure. The way he approaches his job is he makes it fun for us to come in and work for him.”