Andy Murray has pulled out of next week's Madrid Masters because of a back injury.
The world number four hopes to return to action at the Rome Masters the following week in preparation for the French Open, which begins on May 27th.
Murray said: "It is with regret that on doctor's advice I have to withdraw from the Mutua Madrid Open with injury.
"I always love coming to Madrid so it is a big disappointment. I look forward
to returning next year and wish everyone a great week of tennis."
A winner of the tournament in 2008 when it was played indoors on hard court, Murray reached the quarter-finals in 2009 and 2010 on clay, and was knocked out in the third round last year.
This season, the Scotsman has played in two clay court tournaments, reaching the quarter-finals in Monte Carlo and Barcelona.
The Madrid tournament was also hit by the withdrawal of US pair Mardy Fish and Andy Roddick on Thursday, although the world's top three players, Novak Djokovic, Rafael Nadal and Roger Federer will be playing.