Spanish newspaper Marca, external reported last weekend that an unnamed Brazilian club had made an offer to Ronaldo.
Botafogo are one of four Brazilian teams to have qualified and their coach Renato Paiva was asked about Ronaldo, external last Sunday.
He laughed before saying: “Christmas is only in December. But if he came, you can’t say no to a star like that.
“I don’t know anything – I’m just answering the question. But, as I said, coaches always want the best. Ronaldo, even at his age, is still a goal-scoring machine. In a team that creates chance after chance, he would be good.”
Botafogo are owned by American businessman John Textor, who also holds a majority stake in Crystal Palace.
Ronaldo won the Champions League four times during nine seasons with Real Madrid before joining Juventus in 2018.
Real and Juve are among the 12 European clubs that have qualified, which includes Premier League teams Chelsea and Manchester City.
Between them either Ronaldo or Messi won the Ballon d’Or from 2008 to 2017, before Messi won it three more times to give the Argentine forward, 37, a record eight wins.
Messi’s Inter Miami are in the same group as Egypt’s Al Ahly, Portuguese side Porto and Brazilian club Palmeiras.
