How is Neymar doing right now?
With the age of 31 Neymar has been to SPL, he should be 2 or 3 years he can still compete in Europe. Just look at Ronaldo, he went to Arabia when he was not much interested in Europe. In addition, it seems that the money factor makes Neymar and Ronaldo to the SPL.
He can play in Europe and continue his career there but no longer as a super star player. He has become a star player and it's difficult for him to return to his best day and with very good offer from Al Hilal, Neymar decided to leave. It's almost no chance to see him return to Europe if he will continue to receive a lot of money in Saudi Arabia.
It is estimated that the injury he suffered will prevent him from playing for quite a long time, in fact, by the middle of this year, it is estimated that he will still be absent from the field, so if he does not take care of his body, it is very likely that he will become fat, especially if he is not disciplined in maintaining his diet.
We don't have to speculate on how Neymar's body will become after this injury. Even when he played for PSG, at highest level in Europe and Champions League, he usually returned to Paris after each summer with overweight body. Many times we saw this and now he even has better habitat to enjoy eating and his life, in Saudi Arabia. At lower level and maybe less control from his club, it's harder for him to control his body weight.
It seems that there is no player who can compare to Ronaldo in terms of body discipline, that's why there are not many changes in his body shape and fitness, maybe he is no longer as free to run as he was 5-10 years ago but he is always ready to play for his club.
Cristiano Ronaldo is professional from eating to training and playing and it's certainly far more professional than Neymar. Brazilian players have tradition of unprofessional compares to players from Europe. Very few Brazilian players who are professional as I know, Kaka, Cafu, Juninho, just some names.