The midfielder has been strongly tipped to leave the Italian giants this summer, and last week the club confirmed the Portuguese had turned down a move to join Everton on loan.
Tiago, who signed for Juve from Lyon last summer, struggled to hold down a regular place in Ranieri's plans last term, but the former Chelsea boss has admitted he has been impressed by the 27-year-old in recent weeks.
"Tiago is a wonderful lad, an exemplary professional, and if he remains I would happily accept it," he told Rai Sport.
"September is a few days away thankfully and the transfer window will close.
"Has he asked to speak to me? He hasn't spoken to me about these things, he talks with the club about it.
"He knows that I rate him and he is improving."