Last night against the Jets, Giants safety Stevie Brown intercepted a pass and during his return, he went down awkwardly on his own. He remained down for a few minutes, and had to be helped off the field by the Giants' medical staff.
It was initially reported as a sprained knee, but according to USA Today's (and former Giants beat writer) Mike Garafolo, it may be more serious:
Last season, the Giants gave up a boatload of yards (they were 31st in the NFL in yards allowed), but they remained a respectable unit because they were able to force so many turnovers, including 21 interceptions, which was 3rd in the NFL. Stevie Brown had 8 of those picks, which was good for 2nd in the NFL, individually.
The Giants are already thin at safety with Will Hill being suspended for the first 4 games. If Brown is gone for an extended period of time, that could be an enormous loss for them.