The Portuguese ace is said to be keen on leaving the Old Lady before the end of the transfer window.
The Portuguese star joined the Old Lady in the summer of 2018 and has since been their best player, helping them win back to back league titles.
But, the 36-year-old appears to be not interested in continuing with Juve as he and his agent are reportedly pushing a move to Premier League champions Manchester City.
Despite Ronaldo’s overwhelming contribution to Juve’s attack, Gigli, who served as president between 2006 and 2009, says that the club shouldn’t have signed the Portuguese skipper in the first place.
Gigli said: I’ve always been honest: signing Ronaldo was a mistake. It’s impossible to recoup the investment and it will remain that way.
“He’s a great player, but I have to be honest – the sooner he leaves, the better for him and for Juventus.
The erstwhile president also criticised Ronaldo’s style of play, claiming that it is affecting the club’s overall attack.
Gigli added: “I hope that Massimiliano Allegri knows how to continue using him like he did against Udinese. That is, with intelligence and when the game is in progress.
“Ronaldo hampers Juventus’ attack. Without him, they can do excellent things in collective terms.”
The former Real Madrid star appeared as a substitute in Juve’s Serie A opener against Parma after reports emerged that he had requested to start on the bench to sort out his future.
Although Ronaldo dreams of playing under Pep Guardiola, Man City continue to focus on signing Harry Kane.