Here’s my honest thoughts on his ranking - it shouldn’t be a big deal but does have the potential to cause trouble for him at the FO 2021. Here’s why:
let’s say he’s 9th-12th post AO (I’m assuming he doesn’t make a miracle recovery and make the AO final for example).
Rafa will definitely want one of the top 8 seeds for the French Open and thus will schedule MC, Barca, Madrid, Rome in efforts to obtain the top 8 seed. the thing is he’s going to be losing a ton of points if he doesn’t defend Barca, Madrid, or Rome. I don’t want him overplaying on that foot but he may be forced to. Bad idea.
Of course if he wins even one of those he should get back to top 8, and if he can’t win any.. maybe he doesn’t have the clay form to win Roland Garros anyway.
either way going into RG we could see a really tough draw for him as the 9 seed.
something like: 4R Thiem, QF Tsitsipas, SF Zverev, F Djokovic. yeah he’s better than them, when he’s peak Rafa, but I worry the stamina issues in Bo5 could really tire him out and leave him vulnerable for a potential final.
of course it could also be QF Rublev SF Ruud F Tsitsipas which presents less issue. Obviously the draw matters quite a bit. The point is getting a top 8 seed is crucial for the FO, even if he is great form, his stamina is the biggest limiting factor currently.