He suffered a humiliating defeat in Madrid 1st round in front of hometown fans and I would suspect that he doesn't think he's fit enough or able enough to put in a performance (s) that would do justice to a tournament in which he achieved his greatest success. This may indeed be the end of the road for his tennis career and I will miss seeing him perform. An elegant player, a fair player, and a great ambassador for the sport.
Good point Ariel, also Margy's point about him moving slowly.
Yes, the RG site confirms that he has withdrawn: "Three more players have pulled out of the men's singles draw on Tuesday. 1998 winner Carlos Moya, David Nalbandian and Ivo Karlovic have all had to withdraw through injury
OK Agassi retired at 36, but even in 4 years, the pace of the game seems to have moved on significantly. Charly is not even condsidered tall for a player now.
Sad, but I'd prefer him to go now rather than drag on - especially as a whole new life of being a Daddy is opening up before him...
Carlos was my first Armarda "Hottie" and was a great father figure to so many of the current younger players when they first started on tour, as Rafa and David Ferrer particularly have said.
I wish him all the luck in the world for whatever decision he makes and what he does next...