One unfortunate thing from the earlier match with West Ham was the injury picked up by Aaron Ramsey. It appears to be a thigh strain. Arsene Wenger is not sure how long Ramsey will be out for, but he has ruled the Welshman out of the remaining Christmas fixtures. Ramsey knew straight away that he was injured, and immediately came off, to be replaced by Lukas Podolski.
Ramsey had been looking a little off-kilter in recent matches, but had still had a decisive impact in the past three games, with an assist for Theo Walcott, and should have been assists for Olivier Giroud and Theo Walcott. He is also Arsenal's top scorer, of course, and one of the reasons why Arsenal are top of the table. And while he had been a little off-kilter, this idea that he has been run into the ground seems absurd: he recently had a 9 day break, and also didn't play full match against Everton or Napoli.
For the mean time, one of Jack Wilshere or Mathieu Flamini will come into the side, creating a midfield partnership with Mikel Arteta that hasn't proved to be successful as of yet.