WASHINGTON — The NFL players' union filed a grievance contesting the $1 million the New York Giants withheld from Plaxico Burress' signing bonus after he shot himself in the thigh in November at a nightclub.

Legal briefs were filed Friday in the second of the union's two claims on Burress' behalf, NFL Players Association spokesman Carl Francis said Monday. No dates for the grievance hearings have been set.

The Giants suspended the 31-year-old wide receiver for four games after the accidental shooting in Manhattan. Burress was charged with felony gun possession and is due in court March 31.

The union already filed a grievance over what it termed excessive punishment by the Giants. His suspension cost him more than $800,00 in salary. The team also fined him more than $200,000, his single-game salary.

The latest grievance concerns the $1 million the team is withholding from the $4.25 million signing bonus Burress received when he extended his contract last August.

General manager Jerry Reese and coach Tom Coughlin have left the door open for Burress to return to the Giants after his legal difficulties are cleared up.