The attacking midfielder completed his move from Serie A champions Juventus on July 16, underlining Sunderland's ambition to improve on their 17th-place finish last term.
And Di Canio is confident that the 28-year-old Italy international has all the traits necessary to be a success in English football.
"I'm sure Giaccherini will impress everybody," the Italian said.
"There is no doubt about his technical quality. But a player has to change his mentality completely to play here. English football is one of the more difficult leagues in the world - there are many more tackles, fixture congestion and playing in the winter.
"But I was sure about his attitude and desire to come to England. When you sign a foreign player I want to know if he loves English football and if he has a desire to understand English football and integrate himself in English life.
"Giaccherini is a fantastic lad and will be one of the best players in this league. He's a very humble guy but he is one of the best players in one of the best national teams in the world.
"He is still a bit behind [in pre-season preparation] and he's a bit heavy in his legs right now but in the future he will be a crucial player."