Great... on the first day of training camp.
http://sports.espn.go.com/nfl/news/story?id=2120377

ALBANY, N.Y. --Wide receiver Plaxico Burress was taken off the field during the New York Giants' first practice session Saturday morning with what coach Tom Coughlin described as a hyperextended knee.

Burress, the Giants' major offseason acquisition, went up for a long sideline pass from backup quarterback Jesse Palmer and fell to the ground after battling with rookie cornerback Ahmad Treaudo. He grabbed his right leg, then lay on his back for about five minutes while trainers examined him.

Burress later was taken from practice in a golf cart with his right knee wrapped.

The Giants acquired Burress as an unrestricted free agent from Pittsburgh in March. He signed a six-year, $25 million contract that included an $8 million signing bonus.

The sixth-year pro, a first-round draft pick by the Steelers out of Michigan State, has 262 career receptions for 4,164 yards and 22 touchdowns. He is expected to strengthen a Giants passing attack that had the second-fewest touchdown passes in the NFL last season.

Whew, hopefully just a hyperextension--could have been alot worse!

It's anywhere from a couple of days to two weeks. The Giants aren't worried.

Phew! Burress came back to practice later in the afternoon:

http://www.giants.com/news/eisen/story.asp?story_id=7184