Jose Antonio Reyes will miss Arsenal's Christmas holiday programme after twisting a knee in training.
The 21-year-old, who missed the Gunners' win over Portsmouth on Sunday, will also be sidelined for the games against Fulham and Newcastle.
Arsenal boss Arsene Wenger said: "Reyes' knee injury is not too bad but needs treatment and 10 days out."
Freddie Ljungberg should return for the Boxing Day match against Fulham after missing three games with a migraine.
"Freddie had scans and there was a worry over him but he has been given clearance now and hopefully he will be fit for the Christmas games," said Wenger.
However, Brazilian midfielder Gilberto Silva is not expected to return until February as he continues his recovery from a back problem.