I dont think that is even possible since it isnt Nadal's personality. The guy even tries to play tournaments with serious injuries at times (eg- 2007 U.S Open) to the point of hand wringing from even some of us loyal fans. It is so much of what I admire and love about him as a fan, but he also even pushes it to extremes at times, but it is who he is. He will basically give 110% all the time, not skip or not give his all to every event unless to the point of being so sore or so worn out it isnt even physically possible to perform. He will keep doing this his whole carer until his wheels fall off or start to fade, be that at 23, 25, 27, 29, 30-something, whenever. When it happens it will happen, but you will never see that kind of career pacing from him as it isnt in his makeup.