The surgery has altered the course of Mankins' offseason, making it highly unlikely that he will participate in spring minicamps. While Mankins hopes to be ready for the start of training camp in late July, his status is a consideration as coach Bill Belichick builds the team's roster this offseason.
On Monday, the Patriots agreed to a one-year contract with veteran offensive lineman Robert Gallery, who has experience at guard.
Mankins injured his left knee in the Patriots' 27-24 win over the Miami Dolphins on Dec. 24. He missed the season finale -- the only game he's missed in his seven-year NFL career because of injury -- before playing throughout the playoffs. One source said Mankins' injured knee was hit early in Super Bowl XLVI and that it was later determined he had been playing through a torn ACL.
A first-round selection of the Patriots in 2005, the 6-foot-4, 310-pound Mankins signed a six-year, $51 million contract with the team last August.
Mankins' status isn't the only question facing the Patriots' offensive line, as starting left tackle Matt Light is strongly considering retirement, according to sources.