Nadal has signed a contract with Richard Mille, a french watch brand. He will start using those watches at Rolland Garros, he´ll wear the watch on his right arm, and has been testing it since january. It just weights a few grams, but he has to get use to it.
These are the watches (very expensive)
http://richard-mille.com/#
In my opinion he should just be focus on getting well soon and trying to get his coinfidence back and not trying to get use to wear a watch, anyway i hope the watch becomes a talisman.

Never underestimate the pain of a person, because in all honesty, everyone is struggling. Some people are just better at hiding it than others.