McCarthy's ties to the Saints date back to the 2000 season, when former coach Jim Haslett hired him as an assistant. He was originally hired as a quarterbacks coach before Haslett decided to make him OC a week later. He was 36, the youngest offensive coordinator in the NFL at the time.
McCarthy, 61, has a long relationship with both Loomis, who was the Saints' director of football administration at the time, and Randy Mueller, the Saints general manager from 2000 to 2001. Mueller is now helping with the Saints' coaching search in an advisory capacity.