World No. 4 Andy Murray will skip next week's Madrid Masters, citing a back injury.

Murray captured the tournament in 2008 when it was staged on an indoor hardcourt. The event has been played on clay since 2009.

This year the tournament is being played on an all-new blue clay surface, which players have said is slippery and provides a different bounce.

Serbian star Novak Djokovic beat Spanish hero Rafael Nadal in last year's finale at the Magic Box.

The 2012 Madrid Masters will commence Sunday.