You may have noticed that Bear Pascoe was the acting Giants fullback during the final drives and he appeared to have some success in the role. Coach Coughlin has a history of attempting to switch TE's to FB (i.e. Jeremy Shockey) and this move just might stick.
The decrease in run blocking has in part been "credited" to Hedgecock and Pascoe will likely get more looks at the position whether the true FB is healthy or not.
If the injury is severe enough to warrant significant time off, the Giants just may say goodbye to another Super Bowl winning member sooner rather than later.