Keown's absence would be a big blow for Arsenal Player profile: Martin Keown

The 36-year-old, who has been out for three weeks with a hamstring injury, has still not resumed full training.

And fears are growing that if Keown cannot face Neil Warnock's First Division side, he will not be ready for the crunch Premiership encounter with Manchester United on Wedneday.

Keown's absence would be a massive blow as the Gunners bid to claim their second consecutive league and cup double.

Arsenal are already without the suspended Pascal Cygan for Sunday's FA Cup tie, which leaves manager Arsene Wenger with a defensive dilemma.

The Frenchman may have to move right-back Oleg Luzhny, who is just back from long-term injury, into the centre of defence, or give Igors Stepanovs a game.

Keown has been absent from the side in all Arsenal's seven defeats this season and Wenger may wait until just before the 1330 BST kick-off against the Blades to make his decision.