With the Denver Broncos making a serious playoff run at 7-1, coach John Fox is about to take time off to undergo heart valve surgery.

Fox, who it was originally reported had a light heart attack Saturday morning, started feeling his heart giving irregular beats and was rushed to the hospital. He did not have a heart attack, but was told to rest before surgery.

In his absence, Adam Gase and Jack Del Rio will share head coaching duties. The amount of time off has not been determined, though Fox will miss "several weeks."

Fox is 58 and has a history of heart problems.