Lemme try and talk about Djokovic's problem.
Playing tennis requires you to have all the aspects of your game and body to be up to a certain standard. That, to even step on the court. Doing a comeback involves winning your first decent match in the first place and then it goes from there. Is the guy going to be match fit? Probably, so is he ready to take down a top 15 opponent? There are many questions to answer before knowing his chances at the major. It isn't easy to be competitive right now. Even without Murray, Stan and Milos, AO will have tons of landmines and pretenders. And, reaching final won't be easy for Novak here. Even for Roger, it's going to require a pretty good level of game.
We may not see a sea change come 2018. But hey, there could be more trouble for the Big 4.
