The Swiss Football Association this morning posted a statement on their official website suggesting a more positive prognosis than Arsene Wenger's initial post-match comments after Djourou suffered a dislocated shoulder in the FA Cup quarter-final defeat at Manchester United.

The Swiss FA went as far as to suggest the defender could feature in the Euro 2012 qualifier against Bulgaria on March 26, reporting Djourou "had new hope that his season is not over yet" as initial tests showed there were no fractures, while ligament damage was indicated "not to be in a serious condition".

However, it is understood the 24-year-old is in fact expected to undergo corrective surgery later this week following further scans with Arsenal's medical team.

The confirmation of Djourou's absence is another blow as Wenger looks to salvage a campaign which is in danger of falling apart once more.

After suffering Carling Cup final heartache at Wembley, the Gunners then crashed out of Europe in Barcelona before losing at Old Trafford as fighting on four fronts suddenly became just one.

Nevertheless, Arsenal still have the destiny of the Barclays Premier League crown in their own hands, just three points behind United but with a match in hand ahead and a crunch showdown with the Red Devils at the Emirates Stadium to come on May 1.

Given Thomas Vermaelen has yet to feature since the end of August because of a niggling Achilles injury, Arsenal will head to West Brom with Sebastian Squillaci set to partner Laurent Koscielny in a defensive pairing which so far has proved less than effective.

Midfielder Alex Song (knee) has already been ruled out, while captain Cesc Fabregas (hamstring) and England winger Theo Walcott (ankle) are not expected to feature at The Hawthorns.

Striker Nicklas Bendtner - again linked with a move away from Arsenal, this time to Blackburn - should be available after missing the United trip with sickness.

There could be an old familiar face in the Gunners squad once more this weekend should a deal be completed for Jens Lehmann to make a return.

The former Germany goalkeeper, 41, left Arsenal in 2008, but is in talks over a short-term deal to help the club through an injury crisis, with confirmation of his return expected later this week, probably when Wenger holds his scheduled pre-match press conference at their Hertfordshire base on Thursday.

Lukasz Fabianski has been ruled out until the end of the season because of a shoulder problem, while Wojciech Szczesny has been sidelined by an injured finger which he picked up in the Champions League loss to Barcelona, leaving Manuel Almunia as the only fit senior keeper.

Lehmann and Almunia had a difficult relationship when they battled it out for the number one jersey previously.

However, the German, part of the 'Invincibles' team which won the 2003/2004 Premier League, maintains he will give the Spaniard his full support.

"This time I am looking forward to being in a back-up role and will look to support Almunia," he said.

"We can still win the title."

UEFA, meanwhile, are set to rule on their disciplinary case against both Wenger and midfielder Samir Nasri on Thursday.

While the Gunners boss will not attend personally, the club have submitted their observations.

Wenger and Nasri have each been charged for using "inappropriate language" towards Swiss referee Massimo Busacca after the final whistle at the Nou Camp, where Arsenal lost 3-1 after having striker Robin van Persie controversially sent off.

Busacca caused uproar by showing Van Persie a second yellow card for shooting at goal just one second after he had blown the whistle for offside - the Holland forward claimed he had not heard it due to the noise of the 95,000-plus crowd.

Wenger confronted the Swiss official after the final whistle over the sending-off and angry exchanges continued inside the tunnel.

The Gunners boss launched a stern defence when questioned on the charges, blasting Europe's governing body as arrogant and a "dictatorship" when he spoke to the media ahead of the cup tie at Old Trafford last week.