The Denver Broncos named defensive coordinator Jack Del Rio as interim head coach on Monday as John Fox recovers from heart surgery.
Fox was taken to a hospital in Charlotte, North Carolina, on Saturday after feeling light-headed while playing golf. The 58-year-old will be absent from coaching the team for several weeks.
He will undergo an aortic heart valve replacement this week instead of waiting for the offseason, when it had been previously scheduled.
Del Rio will continue his role as the team's defensive coordinator, the NFL team said in a statement on their website (www.denverbroncos.com)
Denver, with a 7-1 record this season, are favorites to win a first Super Bowl since 1999.
(Writing by Justin Palmer in London; Editing by Clare Fallon)