The Redskins announced that they’ve signed free agent guard Hugh Thornton, who hasn’t played in the NFL since the 2016 campaign. Washington also formally announced the previously-reported signing of offensive tackle Donald Penn, and waived center Casey Dunn and guard Tyler Catalina.

Thornton, now 28, was a third-round draft pick of the Colts in 2013. Over his first three seasons in the NFL, Thornton was a contributor, starting 37 total games and earning mostly positive grades — especially in the run game — from Pro Football Focus.

After spending the 2016 season on injured reserve, Thornton inked a one-year deal with the Falcons in May 2017, but announced his retirement just two months later. He ended that retirement earlier this year to play for the Arizona Hotshots of the Alliance of American Football.

Ereck Flowers, who’d been filling in as Washington’s left tackle until Penn arrived, is penciled in as the club’s starting left guard. Despite Flowers’ run of failure in the NFL, it’s difficult to envision Thornton overtaking him for a starting job, but he could add depth to the Redskins’ line.