After retiring from goalkeeping in 1987, he was named Assistant Coach of the Dallas Sidekicks on July 6, 1987. He was then promoted to Head Coach on March 2, 1989 and remained in that position until January 21, 1991. Phillips was named MISL Coach of the Year for 1989-1990. He then returned as the Assistant Coach of the Sidekicks until he was promoted to a front office position in 1996. During his time as assistant coach, the Sidekicks went on to win their second title in 1993 when they were in the CISL.