The Pro Bowler unknowingly played in the Super Bowl with an ACL tear in February and later had offseason surgery. The average recovery time is about nine months, which should take Mankins into November, if not later. The Patriots can put him on the physically unable to perform (PUP) list and not have to worry about his roster spot until six games into the season.
Mankins is a strong possibility to join other big-name players on the PUP such as Terrell Suggs (Achilles) and Rashard Mendenhall (knee). The Patriots have been hush-hush about Mankins' recovery. But chances appear slim he could make it back in time for the Sept. 9 regular-season opener against the Tennessee Titans.
The Patriots quickly gathered insurance in the offseason by signing veteran guard/tackle Robert Gallery. He's experienced and versatile enough to fill in for Mankins.
New England isn't the most forward team with injury information, so don't expect an official announcement any time soon. But I expect Mankins to start the season on New England's PUP list.