DENVER - Denver Broncos' head coach John Fox is spending the night in a North Carolina hospital and reports indicate he will need heart surgery.
Fox was taken to the hospital after "feeling light-headed," the Broncos organization said Saturday.
Sources initially told ESPN that Fox had experienced symptoms similar to a heart attack.
Hours later, Denver Post sports reporter Mike Klis tweeted that Fox would have heart surgery Monday or Tuesday. That would keep the head coach from the sidelines for up to two months.
Klis added that Jack Del Rio was a likely interim coach.
Earlier Saturday, the initial reports from ESPN NFL reporter Adam Schefter said Fox was taken to the hospital for a suspected heart attack. Schefter later added an employee of Quail Hollow Club said Fox complained of chest discomfort while on the course.
Denver Broncos spokesman Patrick Smyth has flatly denied the reports of a heart attack. He tweeted, "Talked to Coach Fox a few minutes ago. Did not have a heart attack. Is in good spirits and undergoing additional testing at hospital."
The Broncos then released a statement that said:
"Denver Broncos Head Coach John Fox was taken to a Charlotte-area hospital after feeling light-headed while playing golf on Saturday. He is being held at the hospital for testing and further observation. Our medical staff is currently in contact with Coach Fox, his family and the doctors who are treating him. Additional information will be provided as it becomes available."
Denver Broncos wide receiver Demaryius Thomas quickly tweeted, "Prayers up for my Coach......."
John Fox, 58, later tweeted from his hospital bed, "I am doing fine. We are just running some tests and will know more in a few hours."
According to the Mayo Clinic, shortness of breath and lightheadedness are two symptoms of a heart attack. Others are chest pain, upper body pain, stomach pain, nausea and vomiting, sweating and anxiety.
The team is on a bye week this week. Fox was spending time at his home in Charlotte, N.C.
He is in his third season with the Broncos in 2013 after being named the 14th head coach in franchise history. Fox, who has experience on multiple Super Bowl teams and is one of six active head coaches with 100 overall wins, joined the Broncos after spending the previous nine seasons (2002-10) as the head coach of the Carolina Panthers.
Fox has appeared in two Super Bowls and three conference championship games as a head coach or defensive coordinator. He has coached 30 players to a total of 57 Pro Bowl selections, including Pro Football Hall of Fame cornerback Rod Woodson and perennial All-Pros such as cornerback Champ Bailey, safety Brian Dawkins, quarterback Peyton Manning and defensive ends Julius Peppers and Michael Strahan.