While still in the CFL, Clements pursued a Juris Doctor degree, finally graduating magna cum laude from the University of Notre Dame School of Law in 1986, and, upon the completion of his playing career, he practiced law in Chicago for five years. In 1992, Clements was hired as quarterbacks coach for Notre Dame, where he served until 1995 under head coach Lou Holtz. After again practicing law in 1996, Clements took his first NFL job, working as the quarterbacks coach for the New Orleans Saints from 1997 to 1999. Clements would hold the same job in 2000 with the Kansas City Chiefs and between 2001 and 2003 with the Pittsburgh Steelers; under Clements’s tutelage, the Chiefs’ Elvis Grbac (in 2000) and the Steelers’ Kordell Stewart (in 2001) and Tommy Maddox (in 2002) each reached the Pro Bowl.
In 2004 and 2005, Clements served as offensive coordinator for the Buffalo Bills, but was released by the team after a front-office shakeup in which Marv Levy, his coach with the Chiefs in 1980, assumed the position of general manager and ultimately installed Dick Jauron as the team’s new head coach. Upon the hiring of Mike McCarthy to be the head coach of the Packers on January 11, 2006, the Packers parted ways with several assistant coaches, and McCarthy later interviewed NFL Europe head coach Steve Logan and Clements before settling on Clements on January 28, 2006.