The New England Patriots have signed free agent guard Darnell Stapleton, his agent, Ed Wasielewski announced on Twitter.

Terms were not disclosed.

Signed by the Pittsburgh Steelers as an undrafted free agent out of Rutgers in 2007, Stapleton started at right guard for the final 15 games of the 2008 season, including the Steelers' win over the Arizona Cardinals in Super Bowl XLIII.

Stapleton missed the entire 2009 season with a knee injury, but is reportedly 100% recovered from that injury, working out for the Patriots last week.

New England is in need of depth at the guard position. Pro Bowl left guard Logan Mankins has not signed his restricted free agent tender and his replacement, Nick Kaczur, could miss the entire season with a back injury.

In addition to Stapleton, the Patriots signed cornerback DeAngelo Willingham and released wide receiver Buddy Farnham and defensive lineman Adrian Grady, ESPNBoston.com's Mike Reiss reports.