Murray was hampered by foot blisters in the AO final, likely due to his 5 setter against Fed in the SF. Djok of course has shown over the last few years that he can go through consecutive 5 set matches without any issues - AO 2012 - vs Murray then vs Nadal - both grueling matches. USO 2011 as well, he beat Fed in 5 sets in a very physical match, then dominated Nadal in the final beating him in 4 sets. Given that both are the same age and have the best conditioning staff, why is Murray not as fit or better? What does he lack, or is it all mental?