[1] After retiring from football, Tillman stayed in the NFL as an assistant coach for the Seattle Seahawks for 16 years, where he coached special teams, tight ends, linebackers before becoming defensive coordinator.

[1][2] He also spent time as assistant with Tampa Bay, Oakland, Indianapolis and Minnesota.

He served as head coach of the XFL’s New York/New Jersey Hitmen;[3] uninterested in the sports entertainment approach the league was taking, Tillman mostly took a straight approach to coaching in the league, refusing to get wrapped up in the publicity stunts.

Tillman was called "Gutless Rusty" by WWF announcer and sitting Minnesota Governor Jesse Ventura, who as part of a publicity stunt, came out of his XFL broadcast booth to try to provoke a response from Tillman near the end of the league's week 4 telecast; Tillman turned away and refused to answer him.

Tillman was a special teams coach in the NFL for the Seattle Seahawks in the 1980s and the Minnesota Vikings under Mike Tice.