Vitt has also been an assistant for the Philadelphia Eagles and Green Bay Packers. He served under former St. Louis Rams coach Dick Vermeil for the Kansas City Chiefs for three years until Martz brought him to St. Louis as the assistant head coach and linebackers coach. It marked Vitt's eighth time in the National Football League, and the second with the franchise. During the 2005 NFL season, Vitt served as the interim Head Coach of the Rams while Martz was out due to a bacterial heart infection. He coached the team from Week 5 until the end of the regular season; soon afterward, Martz was fired. Vitt had a record of 4–7, and was replaced by Scott Linehan in the off-season.