Arsenal defender William Gallas is rated as only 50/50 because of an eye problem for the Barclays Premier League clash with leaders Chelsea at Emirates Stadium.

But full-back Kieran Gibbs is out following an operation on his foot. Veteran Mikael Silvestre is on stand-by to fill in at centre-half while Armand Traore should fill in on the left.

Russian playmaker Andrey Arshavin will be available despite needing staples in a wound after a clash of heads with Gallas against Standard Liege on Tuesday night.

Strikers Robin van Persie (ankle) and Nicklas Bendtner (groin) remain sidelined so England forward Theo Walcott could make only a second start of an injury-hit season.

Goalkeeper Lukasz Fabianski (knee) is close to a comeback but Abou Diaby (calf), Gael Clichy (back) and Johan Djourou (knee) are still out.

Manager Arsene Wenger insists the "moment has come" for his Arsenal side as they prepare to face Chelsea.

The Gunners - who have a match in hand on their title rivals - will be looking to cut an eight-point gap on the Blues after slipping further off the pace in the wake of last weekend's lacklustre defeat at Sunderland.

Confidence within Wenger's squad, however, remains high after they returned to winning ways with a 2-0 win over Standard Liege in midweek to book a safe passage through to the knockout stages of the Champions League.

"Everyone will look at the game to rate our potential and I have no worries about that," said the Arsenal boss. "We are ready for the game, are well focused, prepared and the confidence is good. We just want to focus on the game like we want to play it."

Wenger added: "It is a big test, yes - but that is what you want, to play these teams. I think there is a period for any team to come out and show its strengths. For my team, this moment has come.

"We are not any more a team that has to be considered to be young. I think we have the strengths and we can show that on Sunday that we are strong enough to compete."

Chelsea have been boosted by a fully-fit Frank Lampard ahead of the clash at the Emirates Stadium.

Lampard has recovered from a thigh injury sustained on England duty but despite flying to Serbia for placenta treatment, Chelsea have confirmed the midfielder only underwent standard massage therapy.

Jose Bosingwa (knee) remains sidelined but Michael Essien has shaken off a knee injury to be included in the squad.

Manager Carlo Ancelotti has targeted a long stay at Stamford Bridge because he already feels part of the Chelsea family.

Ancelotti comes up against Wenger's Arsenal at the Emirates Stadium on Sunday and is full of admiration for the Frenchman's longevity in the English top flight.

Wenger has been with the Gunners for 13 years but Ancelotti insists he is not surprised at the length of his stay and would like to go some way towards emulating it in England.

"My objective is to maintain and keep this position for a long time and I can do this if I do a good job and if the club is happy about the job I'm doing. Up to now, the club is happy with the job I've done I think.

"I want to continue and improve, if possible. To maintain the club's position at the top of the Premiership and doing well in the Champions League.

"Wenger is one of the best coaches in the world and has done a fantastic job like Sir Alex Ferguson at Manchester United. My objective is to stay here a long time."

Copyright (c) PA Sport 2009, All Rights Reserved.

Topics:
#Arsenal
#Robin Van Persie
#Sunderland
#Andrey Arshavin
#European News
#Kieran Gibbs
#Lukasz Fabianski
#Football
#Johan Djourou
#Armand Traore
#Mikael Silvestre
#Chelsea
#Premier League
#Alex
#UEFA Champions League
#Manchester United
#Gael Clichy
#Vassiriki Abou Diaby
#Nicklas Bendtner
#William Gallas
#Jose Bosingwa
#Michael Essien
#Theo Walcott