His NFL career sequentially spanned 16 seasons as a member of the Titans, Chicago Bears, Denver Broncos, and Arizona Cardinals.

Leach signed a future contract with the Chicago Bears on January 10, 2002 and attended training camp with the team before being waived on August 26 of that year.

[1] He was featured in an August 2007 issue of Sports Illustrated in which writer Peter King listed the top 500 players in the NFL.

[4] The Broncos released Leach on March 1, 2009 after the team signed free agent long snapper Lonie Paxton.

In January 2016, Leach announced his retirement from the NFL, via Twitter, just days after the Cardinals' loss to the Carolina Panthers in the NFC Championship Game.