Stefano Pioli praised Zlatan Ibrahimovic for his brace against Bologna and said the forward could star when Milan are at their best.
Ibrahimovic, 38, scored a brace as Milan started their Serie A season with a 2-0 victory at San Siro, where Bologna's Mitchell Dijks was sent off late on Monday.
Pioli lauded the forward, but said Ibrahimovic could only shine if Milan were functioning well.
"When the team works, the individuals are exalted and we have great individuality, then Zlatan is a champion and confirms it every time," the Milan coach told Sky Sport.
"The team has confidence, he knows how to play even in difficulties. He knows how to sacrifice himself.
"Then the technical qualities are there and I'm happy that we are able to exploit them."
Milan battled to a sixth-place finish in Serie A last season and are preparing to face Norwegian side Bodo/Glimt in the Europa League third qualifying round on Thursday.
Pioli hopes his team can improve on that finish, saying: "We have to be ambitious.
"Our goal is to continue to grow and improve the position of the last championship.
"We want to return to Europe, we have a difficult preliminary and then we will prepare the championship at its best."