Arsene Wenger is set to seek permission to sign a goalkeeper on loan after it was confirmed Wojciech Szczesny will be out for around six weeks.
The 20-year-old Pole, who started the season as third-choice keeper, suffered a dislocated finger early on during Tuesday night's UEFA Champions League defeat at Barcelona.
Former first-choice Manuel Almunia came on and made some important saves before Barca eventually broke Arsenal's resistance.
But he is now the Gunners' only fit senior keeper as Lukasz Fabianski was already ruled out for the season after shoulder surgery while Vito Mannone picked up a thigh injury on loan at Hull City.
Wenger looks set to ask the Premier League if he can bring in experienced cover as James Shea, 19, and Damian Martinez, 18, are his only other goalkeeping options.
"We need now an experienced goalkeeper as cover for Almunia because Mannone is out for six weeks so we cannot call on him," Wenger told the club's official website.
"Mannone is here at the training ground having treatment, but he cannot play for the next six weeks. We can call him back (from Hull), but he is not available.
"We have Wojciech out - in my opinion for six weeks - and we have Fabianski out for the rest of the season, so we absolutely need some cover in goal."
Almunia looked set to leave during the January transfer window but the Spaniard has been thrust back into the frame ahead of Saturday's FA Cup quarter-final at Manchester United.
And Wenger praised the 33-year-old's application while he saw Fabianski and then Szczesny sneak ahead of him in the pecking order.
"He is very professional, has a very dignified attitude and overall he has done very well," added the Arsenal boss.
"Yes, he has done quite well when he came on and was quite busy in the final part of the game and he did very well."