Washington's Chris Polk has been one of college football's most productive players in the last few years, featuring as the Huskies' lead runner and punishing opponents with his strength and speed. But injury concerns made him an unlikely 2012 NFL Draft pick, and after being passed up 253 times, Polk has signed with the Philadelphia Eagles as an undrafted free agent, according to a report.

Polk's injury concerns were largely about a shoulder injury that he has played with throughout his career, as well as a knee injury prior to the 2011 season that required arthroscopic surgery. But he was named to the All-Pac-12 first team in 2011 despite the injury, and the running back holds Washington's school record for most 100-yard games with 21.

Polk joins an Eagles backfield which features LeSean McCoy, and he may also have to scrap with seventh-round pick Bryce Brown of Kansas State for a roster spot.

For more on the 2012 NFL undrafted free agency signings, follow this StoryStream.