Arsenal goalkeeper Wojciech Szczesny is a doubt for the weekend trip to Premier League champions Manchester City after the Pole was ruled out of the club's Champions League opener against Montpellier.
The 22 year old picked up the injury prior to the victory over Southampton on Saturday, but played on regardless, making a sloppy error allowing Danny Fox to score a mere consolation amid a 6-1 victory for The Gunners.
But having reclaimed the No.1 jersey from Vito Mannone, the injury has forced Szczesny to step aside as Arsenal begin their Champions League campaign against French champions Montpellier.
"Vito, as I told you last week, is very close," manager Arsene Wenger said. "He gets another opportunity now. He has belief and he has the mental strength to deal with that."
"That shows you how quickly football can change.
"Martinez is [ineligible] from the [B] list and Wojciech [Szczesny] and Fabianski are injured. So Mannone will play tomorrow."
However, the injury is so severe that the Polish international could miss The Gunners' crunch Premier League encounter with City, handing Mannone another opportunity to impress.
The Italian kept three successive clean sheets at the start of the season against Sunderland, Stoke City and Liverpool prior to being displaced by Szczesny.
However, the combination of his ankle problem and error against Saints, means Szczesny could be forced to play second fiddle to the unflappable Mannone for the foreseeable future.
Wenger says "it is too early to tell" whether Szczesny, who was one of the club's more consistent performers last season, will be available for the visit to the Etihad Stadium on Sunday where Roberto Mancini's side haven't lost in the league for close to two years.
The Frenchman also has to decide over whether to field Olivier Giroud against his former side with the forward yet to open his account for Arsenal since his summer move Montpellier.
Giroud helped Montpellier claim the first domestic title in the club's history last term to cap a meteoric rise from the lower leagues and Wenger says the turnaround has been remarkable.
"What they did [last season] is a miracle because three years ago they were in the second division," he said.
"They were one point away from relegation to division three in France. Two years later they are champions of France, so what they did is absolutely unbelievable.
"Especially with the competition they faced with Paris St Germain last year when they moved into the final 10 games. I thought that Paris St Germain would take the upper hand but they didn't. They have done something exceptional.
"It is the first time they are champions of France and it is a club of one man - [Louis] Nicollin, the chairman. He took this club when it was in the conference league 25 years ago and made a professional club of it."