Arsenal boss Arsene Wenger says Aaron Ramsey will miss his side's remaining festive period fixtures after suffering a thigh strain in the win at West Ham.
The Wales midfielder limped off after 65 minutes of the
with Arsenal visiting Newcastle on Sunday and hosting Cardiff on 1 January.
"It looks [bad], it looks a thigh strain," said Wenger. "The Christmas period is certainly over for him.
"I don't know how long it will be, we have to see tomorrow morning."
Ramsey's season to remember
Arsenal midfielder Aaron Ramsey has scored 13 goals this season - six more than he managed in his five previous for Arsenal combined
Ramsey has been one of Arsenal's stand-out performers this season, with 13 goals in 27 appearances in all competitions.
The Gunners had fallen behind to a Carlton Cole strike when Ramsey - on the day he turned 23 - pulled up clutching his left leg.
His removal saw Lukas Podolski introduced for his first appearance since suffering a hamstring injury on 27 August.
Arsenal equalised through Theo Walcott before Podolski crossed for Walcott to head his second and the German then lashed in a third himself.
"We had two real wingers from that moment on and he [Podolski] made a huge difference," said Wenger.
"We had good width in the game and that created many problems for West Ham. He has been out for four months, not played one game.
"He will get slowly back to competitiveness and has shown he can have a huge impact. He can score and make goals, provide assists."