Vieira is out of Arsenal's Champions League clash against Panathinaikos on Wednesday after spraining an ankle at the weekend. The French star is also a major doubt for the game against United at Old Trafford on Sunday.
VIEIRA INJURED
Vieira was treated at the club's London Colney training centre on Monday and is desperate to be ready to face United as the Gunners look to extend their unbeaten Premiership record to 50 matches.