Ha? He is playing in Doha just to regain sum of points he will lose in Auckland (if he loses)..hunger never ends!
He has like 2 or 3 tournaments which he WON in the non-countable section. That means he has an incredible insurance even if he can't defend everything in 2013. It's nearly impossible for him to drop anywhere lower than #5 in the rankings in the next few months, even if he tried really hard.