According to Sky Sports News (And at the time of writing this many other media outlets) Szczesny dislocated his finger in the save before being subbed, for Almunia.
As far as I'm aware (I've done it once before) you need to have your finger in a splint for at least a month and if there's ligament/tendon damage it needs additional rest after that, too.
Meaning quite basically; we'll have Almunia back as our #1 for at least a month, maybe longer.
Let's just hope today's form (loss or not), shows he can bring his A-Game for as long as we require him until Fabs/Szczesny are back from their respective injuries.
Arsenal goalkeeper Wojciech Szczesny suffered a dislocated finger in Wednesday's 3-1 Champions League defeat to Barcelona at the Camp Nou.
Szczesny was hurt saving Dani Alves' 16th-minute free-kick and was replaced by Manuel Almunia after treatment.
Arsenal boss Arsene Wenger said he did not know how long the Polish keeper would be sidelined.
"We have to check the tendon to see how much treatment it will need. We don't know yet," the Frenchman said.
The injury is a particular concern for Wenger given that Szczesny's compatriot Lukasz Fabianski was recently ruled out for the rest of the season following shoulder surgery - an injury that arose from saving Szczesny's shot in a pre-match warm-up in January.
In addition, Vito Mannone has been troubled by a thigh injury while on loan at Hull, which may leave Wenger to draw on inexperienced young professionals or enter the emergency loan market should Szczesny be sidelined for a lengthy period.
Outside the transfer window, a club must apply for special dispensation from its governing body, such as the Premier League, to make a loan signing - if, for example, all its goalkeepers were injured.
http://news.bbc.co.uk/sport1/hi/footbal ... 419371.stm
I love how this article talks about calling up inexperienced youngsters, or going out for an Emergeloan for a GK if it's a long time; but beside talking about him coming on as a sub, doesn't mention Almunia covering whatsoever.
Unless they mean as cover for Al?