Since Nadal needs a lot of rythm, I don't see him doing well at either IW nor Miami.
Nadal's goal this year is to win RG, Wimbledon, and to retain the OL gold.
He simply wants to build up his form slowly in order to peak during May-July.
If Djokovic fails to defend his titles, Federer might make a move for #1, is my crazy thought.