After playing college football for Portland State, he was signed by the Philadelphia Eagles as an undrafted free agent in 2012.

Rau was signed by the Philadelphia Eagles as an undrafted free agent following the 2012 NFL draft on June 14, 2012.

After playing the entire preseason with the team, he was released during final roster cuts on August 31.

He was re-signed to the team's practice squad on September 1, and was promoted to the active roster on December 8.

[1] Rau made his NFL debut on December 9 against the Tampa Bay Buccaneers.