Sarri replaced Massimiliano Allegri as Juve boss in the summer of 2019 and, despite winning the Serie A title, was dismissed following the club's exit in the Champions League round of 16 against Lyon.
Ronaldo finished that campaign with 30 Serie A goals -- the most in a single season during his time in Italy -- and Sarri said managing Ronaldo is not easy, despite his incredible numbers.
"Ronaldo's management is not simple, from all points of view," Sarri told radio station Sport Italia. "He is a multinational company; he has personal interests that must coincide with football.
"His interests go beyond what is normal, beyond the team or club. I am a coach, not a manager. Ronaldo, however, brings the numbers at the end of the year.
"But in recent years, I hear a lot about players and little about teams."
Sarri also said his success at the club was not appreciated as Juve, having replaced him with Andrea Pirlo as manager, only clinched Champions League football on the final day as results elsewhere saw them sneak into fourth place.
"The Scudetto was taken for granted at Juventus, both on the outside and on the inside," he added.
"We didn't even celebrate. Everyone went to dinner on their own.
"Probably the best year to go to Juventus was this, the fourth place was celebrated. In football, victory is not a foregone conclusion. Sometimes you work hard and you can't win."
Sarri also said that Jorginho, whom he managed at Empoli, Napoli and Chelsea, is finally being appreciated and should be a candidate for the Ballon d'Or should he win Euro 2020 with Italy, having already clinched the Champions League this season.
"If he wins the European Championship, he is a candidate for the Ballon d'Or," Sarri said. "He is a refined player, and that's why everyone doesn't understand him.
"He makes everything seem easy -- it is his greatness. When I went to Chelsea, we managed to snatch him from Manchester City.
"At first it was hard to understand him, the fans, the journalists, now I see that he is appreciated. He was also the captain of Chelsea."