Didn't you ask somewhere what the "mysterious illness" was? He says on lequipe.fr it was just a little gastroenteritis he had in Moscow. He means he's feeling better now, just felt a bit tired at the end of the 1st set, but was able to bounce back.
And he says he likes coming back to Lyon because he played great tennis there, but on the other hand, it was 6 years ago already and that's tough to accept. He's really cute when he says that in his video interview:
He definitely smiles more lately!