The Japan boss believes that the Rossoneri's new signing has the character to succeed in Serie A, adding that he is surprised that he has not moved to a big club sooner
Honda scored 28 goals in 127 games for CSKA Moscow before moving from Russia on a free transfer this month, signing a three-and-a-half-year deal with the Rossoneri.
Zaccheroni believes that the midfielder has all the qualities to make a positive impact at the club, most notably due to his strength of character.
"In my view, he is a top player," the 60-year-old told Gazzetta dello Sport.
"He's certainly a great signing and I am astounded Keisuke hadn't reached one of the most important leagues before. Perhaps it was the transfer fee causing the problem, as it wasn’t easy for Milan to take him away from CSKA Moscow.
"He has character as well as strength, technique and stamina. He’s naturally left-footed, has a great shot, takes good free kicks and is very difficult to knock down.
"It won’t be easy to win a place in Milan's first team and he’s been handed the No. 10, which is a sign of the expectations placed upon him. But Keisuke can bear the responsibility."
As Japan head coach, Zaccheroni has led his side to the 2014 World Cup and has been impressed with what he has seen from Honda on international duty.
"Honda is an atypical Japanese player, even though he himself is very tied to his homeland," the former Milan boss added.
"When he talks, it is never something banal.
"He’s a character and that is essential at Milan. You could have the technique of Diego Maradona, but if you don’t have character then you won’t last long at Milan."