The Juventus attack is significantly weaker with last season's Serie A top scorer returning to Manchester United after spending three years in Turin.
Juventus did re-sign Moise Kean on deadline day, but Alessio Tacchinardi feels Ronaldo has left the Serie A giants in a tough situation after the timing of his departure.
"Ronaldo should have left in a different way, not on his private jet while [Massimiliano] Allegri was talking to the team before the game against Empoli. I expected a press conference to say goodbye to the fans. They deserved something different.
"There are no more legends such as [Alessandro] Del Piero, [Francesco] Totti, [Paolo] Maldini or [Javier] Zanetti, but it wasn't nice to hear from Ronaldo that he was going back to a place he feels like home.
"He put Juventus in a difficult situation, leaving a few days before the end of the transfer window, it is impossible to replace a goal machine like him."