Ex-Charger Assistant to Lead Raider Defense : Pro football: John Fox replaces Gunther Cunningham, who will coach linebackers.

The Raiders have hired John Fox, defensive backfield coach of the San Diego Chargers, to be their new defensive coordinator, replacing Gunther Cunningham.

“This does not in any way jeopardize Gunther Cunningham’s position as a member of the Raider coaching staff,” a Raider spokesman said Thursday.

Cunningham is expected to continue coaching the linebackers.

Another change will occur on offense. Joe Scannella, coach of the offensive backs, is retiring because of imminent replacement surgery on both knees. He has just completed his 41st year of coaching and has been with the Raiders since 1987 in this, his second tour of duty with the team. The Raiders are expected to shuffle the current staff to replace Scannella rather than hiring anybody else.

The hiring of Fox, 39, ends a search that had been going on since the Raiders’ season-ending 29-23 loss to the Buffalo Bills in the second round of the NFL playoffs.

Among those reportedly considered was Richie Petitbon, who was fired at season’s end as head coach of the Washington Redskins.

Fox has been coaching defensive backs in the NFL for the last five seasons, spending three years with the Pittsburgh Steelers before joining the Chargers.

His first full-time coaching job was in 1979 with U.S. International University, where he worked under then-athletic director Sid Gillman, a Hall of Fame pro coach, and Tom Walsh, then the head coach at USIU, currently offensive coordinator of the Raiders.