The Eagles will retain a key defensive piece in 2015, as the club and Cedric Thonrton agreed on a second-round tender worth $2.356 million Monday.

A Southern Arkansas product who got his start on the Eagles practice squad in 2011, Thornton started all 16 games in the middle of Chip Kelly's 3-4 defense last season and has been a stellar run-stopper for the Eagles in recent years. He had 51 combined tackles last year.

With the tender, other teams would need to sacrifice a second-round pick to Philadelphia in order top sign him. He will be an unrestricted free agent in 2016.

The only unsigned restricted free agent left for Philly is running back Chris Polk.

With the offensive line and linebacking cores looking strong and deep, the Eagles can turn their attention to their secondary and offense in the upcoming draft.