Manchester City is considering an option to buy the Portugal forward after its top target, Harry Kane, said Wednesday he was staying at Tottenham for now.
Allegri returns to the scene of his greatest triumphs after two years out of the game, and is one of three big coaching names to retake their place on the sidelines.
The former midfielder, who enjoyed trophy-laden spells as a player at AC Milan and Juve, led the Turin giants to the Italian Cup and Italian Super Cup titles in his brief reign.
Massimiliano Allegri irritated by criticism as Juventus fail to kill off Tottenham in Champions League
Allegri insisted he would not be getting depressed despite criticism at failing to land the killer blow against Tottenham.