We'll see. It could be wise to, though, Nole or Murray will probably be waiting for him less than 24 hours later. The group B is at a huge disadvantage in this respect, especially Federer who due to age and mileage can't recover as fast between matches as he once did.
Federer has won five best-of-three tournaments this year playing QF-SF-F on consecutive days. I don't think this scares him enough to make provisions for it.