Gibbs spent the first half of his adult life at Oklahoma as a player, assistant coach, and head coach. He played for the Sooners as a linebacker under Switzer from 1972 to 1974. He began coaching in 1975 as a graduate assistant under Switzer and was promoted to linebackers coach in 1978. He was promoted to defensive coordinator in 1981, and held that post through the 1988 season. In 1989, Gibbs was named head coach after Switzer was forced out following NCAA sanctions and a number of highly-publicized off-the-field issues involving the Oklahoma football program .