Well he did skip W after that so let's give him the benefit of the doubt.
To be honest i don't think he was injured in neither the Sod match, nor the Rosol match, but this is none of my business anyway.
What is even funnier is that some people really believe Nadal would have won AO 2011 without the injuries. They should better consider that injury a blessing in disguise, otherwise, he would have suffered 3 slam losses in the same year to Nole