Bennett, injured in the third quarter on a low hit by 49ers
safety Erik Totten, underwent an MRI on Saturday that revealed more
damage than originally diagnosed.
He won't play in Thursday's preseason finale at Seattle and is
questionable for Minnesota's season opener Sept. 12 against Dallas.
"He might be a little iffy for the opener," Vikings coach Mike
Onterrio Smith, Bennett's top backup, likely will miss the first
four games of the regular season for violating the NFL's
Foot and ankle injures limited Bennett to just eight games last
season. He finished with 90 carries for 447 yards and one touchdown
-- a significant dropoff from his numbers in 2002, when he was named
to his first Pro Bowl.
Left tackle Bryant McKinnie, who also injured his right knee on
the same play as Bennett, has a mild sprain. He will sit out
Thursday as a precaution, but should be ready for the regular
Backup Adam Haayer will start at left tackle Thursday.