The Seattle Seahawks announced that middle linebacker Lofa Tatupu underwent arthroscopic surgery on both knees today.

Team doctors Ed Khalfayan and Mike McAdam performed the procedures at Seattle Surgery Center.

After missing 11 games in 2009 with various injuries, Tatupu played through his knee injuries in 2010, totaling 88 tackles with a quarterback sack and a 26-yard pick-six in 16 games.

According to my personnel tracking, which appeared on the Tacoma News Tribune's Seahawks Insider blog, Tatupu logged 1,043 of the team's 1,074 defensive snaps (97.1%) this season, only coming out of lineup in blowout wins and losses.

The three-time Pro Bowler is signed through the 2015 season, and is scheduled to earn $4.35 million in base salary next season.

Seattle also announced the signings of defensive tackle Jay Alford, safety James Brindley, and wide receiver Chris Carter to futures contracts.

Brindley, who played his college ball at Utah State, was with the Seahawks last off-season, but was released at the start of training camp. Carter (5-11, 191) played his college ball at UC-Davis, but was coming off a PCL injury and unable to workout at the Combine or his pro day.

Carter worked out for the Seahawks earlier this month.

Alford (6-3, 304) was a third-round pick (81st overall) out of Penn State by the New York Giants in 2007. Alford has 18 tackles and 3.5 quarterback sacks in 36 games with the Giants (2007-08) and Oakland Raiders (2010).

In addition to his regular season totals, Alford has 7 tackles and a quarterback sack in 5 playoff games, with his quarterback sack coming on a 2nd-and-10 play with 25 seconds remaining in the Giants' win over the New England Patriots in Super Bowl XLII.

Alford missed the 2009 season with a knee injury, and was released by the Giants last September.