Well General Hercules, it helps to have a great plan for Australia. If you decide to play winter exhibitions and goof off, and you are a player that depends on supreme fitness, you are asking for trouble. Everyone is looking to be in form and fit that early in the year.
Now finally, finally, Rafa is out for the year. Not sure why he wasted time in Shanghai and Basel after being diagnosed with appendicitis. If he had it taken care of right away, there's an excellent chance he would have been ready for at least the World Tour Finals, which he deserved to be in considering the first half of the year. But he didn't, who knows why? Maybe because of a contract obligation with Basel? Seems that if he had appendicitis, he could have broken that contract. He can't need the money that badly. Only they know why they did what they did.

Anyway, Borna Coric played very well, and did Rafa a favor and knocked him out in Basel. Now Rafa can get the damn appendectomy surgery finally and start preparing for Australia. But he's guaranteed himself #3 ranking going into Australia, for all that it matters. Nole and Roger will be #1 and #2 or the reverse depending on Paris, World Tour Finals, and maybe Davis Cup Finals. It might be interesting to see what they do over the winter. Play in this new league I guess. If it's only a few days then I guess it doesn't matter as long as they don't hurt themselves. But once they take their holidays, they will get down to training. Federer is scheduled for Brisbane like last year. I think No1e will probably just play those exhibitions at the start of the year like in Abu Dhabi. Nadal might try to defend Doha if he can be ready. Let's see if he trains on his indoor hard court, or on clay. Murray will probably be in Miami training then he has Abu Dhabi and Hopman Cup.
I'm not ready to predict anything yet. I'll wait till the draw and see everything that went on over the winter and prep matches.

Respectfully,
masterclass