(Denver, CO)  --  Defensive coordinator Jack Del Rio has been named interim head coach of the Denver Broncos.  Del Rio has head coaching experience, as he guided the Jacksonville Jaguars from 2003 until 2011.  The move was made after head coach John Fox was taken to the hospital over the weekend after he became dizzy while golfing in Charlotte, North Carolina.  Fox will undergo heart surgery this week to replace a valve and will miss four-to-six weeks.  Fox could return to the team by the end of the season, or prior to the team's first playoff game.  The Broncos were on a bye this past weekend and will travel to San Diego to take on the Chargers on Sunday.