A six-time Pro Bowl selection, Allen retired after the 2001 season and is currently an NFL analyst for Pac-12 Networks.

In 2019, he served as the defensive backs coach for the San Diego Fleet of the Alliance of American Football (AAF).

While with the Eagles he was a very popular player with the "Gang Green" Defense, playing with NFL greats Reggie White, Seth Joyner, Jerome Brown, Clyde Simmons, Andre Waters, Byron Evans, Mike Pitts, and Wes Hopkins.

His teammates honored him with the first annual Eric Turner award for the Raiders' most outstanding defensive player.

On December 19, 2018, Allen was named defensive backs coach for the San Diego Fleet of the Alliance of American Football.