Arsenal midfielder Aaron Ramsey is out of the London derby with Chelsea.

Speaking ahead of the visit to West Brom on New Year's Eve Arsene Wenger confirmed that Ramsey would not have recovered in time, nor would he be available for the following league game on January 3.

Ramsey is struggling with a hamstring injury.

He faced a race against time to recover in time for the London derby after suffering the latest muscular problem in the 1-1 draw at Southampton on December 10.