He played college football for the UCLA Bruins, earning All-American honors.

In his rookie season, he helped the Steelers defeat the Arizona Cardinals in Super Bowl XLIII.

Davis attended Clear Creek High School in League City, Texas.

At the University of California, Los Angeles, Davis played defensive end.

On the year he recorded 45 tackles (32 solos) caused two fumbles and recovered another and deflected nine passes and defensed 3 others.

Davis ranks second in school history with 29 quarterback sacks, topped only by Dave Ball's 30.5 (2000–03).

[4] After spending the remainder of the season on the practice squad, he was re-signed to a future contract on January 13, 2010.

On October 5, 2010, the Oakland Raiders signed Davis to their active roster to help bolster the team's injury-depleted linebacker corps.