His draw is relatively easy until the QTR but then it gets essentially tougher for him (Tsonga/Federer, possibly Nadal and then Nole) and given that these are also the biggest matches in the tournament, it is justified to have a bit easier rounds early on. Also, we still don't know what kind of form he is in until he faces a worthy opponent and if he will be able to play all the way to the final set, if things get pushed that far. So there's a lot still unknown. He still touches his back from time to time but perhaps more out of habit but also, probably wants to make sure his back is doing okay so far.
Federer's draw is the toughest one at this point without a doubt. The draws tend to change a lot as they go through different rounds so I don't feel it's ideal to make too much fuss about draws being tough for one particular player or the other. Anyway, Federer's draw is tough from the 4th round with Tsogna, probably Murray and Nadal and perhaps Nole in the final. It can't get tougher than this. But because Federer has too many titles behind him and because he's had his fair shares of nice draws and schedules, I feel it's okay to have tough draws once in a while. And besides, he's kind of sliding down performance wise so the draws aren't going to be easy for him anyway, with one too many players having the ability to beat him even on a good day.
I don't want to say anything as to who I'd like as Andy's opponent in the qtr as Tsonga is in form right now and Federer too is looking sharp in this tournament.