Britney Spears may be kicked off a concert to kick off the 2003 NFL season. So reports the New York Post's Page Six. "Spears could lose her plum headlining gig ... if she doesn't curtail her hard-partying ways, says our source,'' the paper said Monday. "We hear that the league has asked Spears to play a concert in Washington, D.C., in September to kick off the season. But because of a steady stream of sightings in Page Six of a tipsy Spears partying at Manhattan hot spots, the NFL is threatening to drop her from the lineup.''