I'm not normally one for giving highly paid and pampered sportmen excuses;
Whoever scheduled an away Ashes tour consisting of 2 T20's and 7 ODI's all played within a month, starting 3 days after finishing a 5 Test match series played over 6 weeks, directly before a World Cup that could also last for 6 weeks (for the finalists anyway) needs bloody shooting.
Forget the physical side, they must be mentally shot to bits. Even i'm over Cricket now and i'm usually a Cricket tragic.