He previously served as an assistant coach for the Jacksonville Jaguars, Chicago Bears, Tampa Bay Buccaneers, San Diego Chargers, and Grossmont College.

Polk attended Guilford High School in Rockford, Illinois, where he was a standout linebacker for the Vikings football team.

As a senior, he recorded 152 tackles, 13 quarterback sacks, 3 fumble recoveries, 3 blocked kicks and one interception.

He received All-conference (three times), All-state, USA Today All-American and Northern Illinois Conference-9 Defensive Player of Year honors.

[3] As a rookie, he played 6 games on special teams, finishing with 4 tackles after being placed on the injured reserve list with a torn rotator cuff injury on November 14.

[6] In 2005, he suffered an Achilles injury in the final off-season coaching session and was placed on the injured reserve list on July 28.

[11][12] On October 16, 2008, Polk was signed as a free agent by the Dallas Cowboys, reuniting with head coach Wade Phillips, who was his defensive coordinator with the San Diego Chargers.

In 2010, Polk was hired by the San Diego Chargers as their assistant special teams coach.