Obviously very disappointing for Rafa and Tennis. Hopefully he can comeback very soon although I doubt he will return until a clay court event at this point.
Rafa's absence means the draw will leave a lot more room for someone outside Nole, Fed, or Murray to make a run for the title.
no, it doesn't change anything. Rafa wouldn't be a contender anyway and he knew it. Everyone knew it, even the bookies.
So it's still Nole, Fed, Muzza and Pony for the titlle and noone else.