In January 2007, Garrett was hired by the Dallas Cowboys as offensive coordinator. He guided the Cowboys to the 2nd best offense in the NFL, which made him an attractive head coaching prospect. In January 2008, Garrett interviewed for the head coaching job of the Baltimore Ravens and the Atlanta Falcons, receiving offers from both, but ultimately opted to remain in Dallas. His salary for the 2008 season was nearly $3 million; the highest salary for an assistant coach in the NFL at the time. On December 29, 2008, the Detroit Lions received permission to speak to Garrett regarding the team's head coaching vacancy according to ESPN sources. In January 2009, the Denver Broncos also interviewed him as a possible replacement for fired coach Mike Shanahan. He was also a finalist for the St. Louis Rams head coaching position, to replace Jim Haslett, the interim head coach. Ultimately, he lost the Rams job to Steve Spagnuolo.