The Arizona Cardinals have requested permission to interview a pair of Pittsburgh Steelers assistant coaches for their defensive coordinator vacancy, Kent Somers of The Arizona Republic reports.

Arizona has requested to interview Steelers linebackers coach Keith Butler and defensive backs coach Ray Horton, as well as Green Bay Packers assistant head coach/inside linebackers coach Winston Moss, for a position that opened up after Bill Davis was fired.

Davis is currently the Cleveland Browns linebackers coach.

Moss, who played 11 seasons in the NFL with the Tampa Bay Buccaneers, Los Angeles Raiders, and Seattle Seahawks, has been a candidate for head coaching and defensive coordinator opportunities in recent years. 2010 was Moss' fifth season with the Packers, and his third as assistant head coach.

According to Somers, Butler is under contract, while Horton's contract is expiring. Mike Jurecki of XTRA-910 in Phoenix reports the Steelers denied the Cardinals' request to interview Butler.

Butler has coached the Steelers linebackers since the 2003 season and is believed to be the storied franchise's defensive coordinator-in-waiting. During Media Day before Super Bowl XLV, Butler told reporters that there was no clause in his contract stipulating that he'd take over for 73-year old Dick LeBeau, whose contract is also expiring this off-season.

LeBeau plans to continue coaching with the Steelers.

Horton has spent the last seven seasons with the Steelers, and was promoted to his current position when Mike Tomlin became head coach in 2007. Horton played safety for the Cincinnati Bengals, who selected him in the second round of the 1983 NFL Draft out of the University of Washington.