Dallas Cowboys owner Jerry Jones and coach Jason Garrett have focused their search for a defensive coordinator on longtime NFL assistant Monte Kiffin, according to team and league sources.
Kiffin was at the Cowboys' Valley Ranch facility on Thursday and met with Jones and Garrett, according to sources.
It is unknown whether the 72-year-old Kiffin has been offered the job, but he has emerged as the leading candidate from a list that also includes Ray Horton, the former Cowboys player and current Cardinals defensive coordinator who has interviewed for several head coaching positions recently.
If Kiffin is hired, the Cowboys would be switching from a 3-4 defensive front to a 4-3, forcing pass-rusher DeMarcus Ware to play defensive end, with his hand on the ground for the first time in his career.
Kiffin resigned as defensive coordinator at USC, where his son, Lane, is the head coach, and expressed his desire to return to the NFL.
Jones, Garrett and Kiffin could not be reached for comment.
Andy Reid was interested in appointing Kiffin to be his defensive coordinator when he took over the Kansas City Chiefs, but Kiffin was not interested in that opportunity.
Kiffin has been an NFL defensive coach for 26 years, half of those with the Tampa Bay Buccaneers, where he helped the franchise win its only Super Bowl after Jon Gruden replaced Tony Dungy.
Garrett was a backup quarterback with the Bucs in 2004 when Kiffin was the defensive coordinator.
Kiffin is creator of the Tampa-2 defense and is the mastermind of one of the most successful defenses in league history.
The Bucs ranked in the top 10 in fewest yards and points allowed 10 times, a league record.
The Cowboys fired Rob Ryan on Tuesday after two seasons as defensive coordinator.
ESPN senior NFL analyst Chris Mortensen and ESPNDallas.com's Todd Archer contributed to this report.