Arsenal manager Arsene Wenger says goalkeeper David Ospina will be sidelined for at least three months.
The Colombia international was expected to replace suspended Wojciech Szczesny in today's Champions League game against Anderlecht but having been rushed back in the game against Galatasaray, the 26-year old will now be out until the end of the year.
"Look, we have lost only one game in the Premier League but we have not enough points with what we produced," Wenger said during Tuesday's press conference.
"Top level performance is to make the maximum with your potential and sometimes in games you need a fraction more.
"That's what we want to do - give a fraction more to be really efficient in what we do.
"Chambers is back in our squad after suspension. Coquelin is not in the squad. Szczesny is not here as he is suspended and will be replaced by Martinez.
"[For David Ospina] it is exactly the same one [as from the World Cup].
"He had his first injury at Nice - it was a knee problem and he was a bit rushed back and did not use his leg, so his muscle became weaker.
"Then he got injured in the World Cup. After that, he came to us injured after the World Cup and it took him two months to play again.
"I had to bring him on against Galatasaray without a warm up and being prepared, so he had a recurrence of that injury.
"It means he is out for two to three months, now we have to be really careful because it is a recurrence of a thigh injury, which is very difficult.
"It is a long-term injury."
