Zook and Mularkey served on the Pittsburgh Steelers' coaching staff from 1996 to 1998, Zook as special teams coordinator and Mularkey as tight ends coach.
Khan is a major donor to the University of Illinois, where Zook coached from 2005 to 2011. Zook was fired after the 2011 season. His overall record at Illinois was 34-51. He went 23-14 in three seasons at Florida from 2002 through 2004.
Defensive coordinator Mel Tucker, defensive line coach Joe Cullen, linebackers coach Mark Duffner, defensive assistant Brandon Blaney and assistant special teams coach Craig Aukerman have already signed up to work for Mularkey.