....does Nadal no longer use his USO 2010 serve?
I imagine if he did, he'd be very hard to defeat on any surface, not just clay.
I've often wondered this myself. His serving in the 2010 US Open really was a complete outlier to the rest of his career. I believe in that tourney his first serve averaged 119mph. In his second fastest serving tourney -- and there are several of them tied for second -- he averaged 116 mph.
Him serving faster in the 2010 USO was obviously a planned strategic move. And it worked out for him, which makes me wonder why he hasn't gone back to it. If it hurts his shoulder then just use it for the US Open, or even just certain matches in the US Open.