Juventus struggled last season to secure a Champions League spot after missing out the Serie A title to Inter Milan, resulting to the sacking of Andrea Pirlo.
And with the return of Allegri to replace departed Pirlo, the 53-year-old urges Portuguese forward Ronaldo to go the extra mile.
"Ronaldo is a great player and a smart guy. I spoke to him yesterday as I did with the others. I told him that this is an important season and that I am happy to meet him again, now he has more responsibility, because three years ago we had a more experienced team, while now there are younger players," said Allegri.
"I expect a lot more from him in terms of responsibility, he is in good condition and he is fit. There are different moments in a season, playing one game every three days I'll need to rotate the team, involving all the players. I imagine the players' management wasn't easy during the last year and a half," he added.
Cristiano Ronaldo's future at Juventus became the talk of town when the former Manchester United was linked with a move to French giants Paris Saint-Germain following a torrid season last time out.
Ronaldo scored 36 goals in 44 appearances in all competitions for Juventus last season.
The five-time Ballon d'Or winner joined up with his teammates for the pre-season exercise at Continassa on Tuesday.
The rumours of Ronaldo to a different club will now end as the former Sporting player will play out the remainder of his contract with Juventus.
A Champions League title, which still remains the utmost goal for Juventus was the reason why Juventus signed Ronaldo from Real Madrid and will be chasing for the accolade once again.
Juventus will kick start the 2021-22 Serie A campaign away with Udinese on August 22.
