Arsenal have said they will be without defender Sokratis for a month, while captain Laurent Koscielny is being reviewed on a daily basis after suffering a suspected broken jaw.
The Gunners face an injury crisis after the two injuries in Friday's home FA Cup fourth-round defeat to Manchester United left them with only one fit recognised central defender.
Sokratis was replaced after 21 minutes after appearing to twist his left ankle, while Koscielny took a blow to the face from Romelu Lukaku and had to be replaced in the 64th minute.
Manager Unai Emery was already struggling for options at the back before the 3-1 loss after cruciate knee ligament injuries ruled out two other defenders, Rob Holding in December and Hector Bellerin on Sunday, for the season.
Asked how bad the injuries were after the game, Emery said: "I think this is not a big injury to Sokratis, it is his ankle, and Laurent Koscielny is going to hospital to do the analysis.
"Maybe he has broken here," Emery added pointing to his jaw. "I hope not, but we have to wait."
But on Sunday, Arsenal posted a message on their website to confirm that Sokratis had injured his left ankle and was "expected to return to full training by the end of February," with Koscielny being reviewed after suffering "bruising and soft tissue swelling to face and jaw."
Emery said the injury problems contributed to the defeat against a United side who have now won all eight matches under caretaker manager Ole Gunnar Solskjaer.
The visitors took a two-goal lead through former Arsenal forward Alexis Sanchez and Jesse Lingard before Pierre-Emerick Aubameyang pulled a goal back ahead of the break.
"At 1-2 I think we were in this moment with the possibility to draw or to take the possibility to win," Emery said. "But I think these injuries, above all the second injury with Koscielny, didn't help us.
"Two injuries change a lot our possibilities."
United substitute Anthony Martial wrapped up the victory with a late goal.