sentences:  Before joining the CFL, Popp helped form a new pro football league called the Professional Spring Football League in 1991-1992, with which Popp served as the league’s director of player personnel and worked with former NFL Coach Walt Michaels.In 1991, he served as the wide receivers, special teams coordinator, and strength and conditioning coach for the Raleigh-Durham Skyhawks of the World League of American Football (later NFL Europe), under NFL great, Roman Gabriel.Popp first taste in coaching came at Michigan State (1986) under Coach George Perles.