The Carolina Panthers signed center Gino Gradkowski to a three-year deal. He'll back up center Ryan Kalil. "He gives us depth at center and guard,” Panthers coach Ron Rivera said. “You feel very secure that if something were to happen, you can plug him in and not lose everything. It’s very much like with Fernando last year when something happened with Kalil, he had to come in and start the Indianapolis game. We believe that’s what Gradkowski can do for us.” A former fourth-round pick of the Ravens, Gradkowski was traded to Denver in 2015, but was waived in final roster cuts. He was claimed by the Falcons, and played three games with them last year, starting one. Follow me on Twitter; @AaronWilson_NFL Aaron Wilson covers the Texans for The Houston Chronicle.