Paulo Fonseca warned his Milan side they to be "defensively perfect" to get a result at Bayer Leverkusen in Tuesday's Champions League clash.

Milan suffered a 3-1 home defeat to Liverpool in their European opener despite Christian Pulisic firing the Rossoneri into a third-minute lead.

The Serie A giants will be looking to get off the mark at the Bay Arena but head coach Fonseca said they must be flawless at the back.

"I don't think about changing (much), we need to have continuity. We know it's a different game, (but) I think it will be a similar game to the one against Liverpool," Fonseca told a press conference on Monday.

"Defensively I think the team has grown, it's a good test to see our defensive capabilities at the moment. I told the players that to beat a strong team like Leverkusen we need to make a defensively perfect team."

Xabi Alonso's Bundesliga champions began their campaign in Europe with a 4-0 win at Feyenoord but they have conceded 10 goals in their first five league games after letting in just 24 in 34 matches in the 2023-24 domestic season.

Seven-time European champions Milan, the only Italian side to triumph more than once in the Champions League era, are the top scorers in Serie A with 14 goals in six games this term.

"It is true that we have done well in the league in the last few games, but I have to say that Serie A is very different from these games we have in the Champions League," Fonseca said.

"Today I was made to read Xabi Alonso's words. When we talk about Italian teams, we always say the same thing - that (they) are good at defending and playing on the counter-attack. I would like other things to be said when we talk about Milan.

"We don't want to be like that. Tomorrow we will obviously defend because we will play against a very strong team, but when we have the ball we still want to play.

"I'm curious to see the team's behaviour in a different game to those we had in Serie A."

Milan may be without Spanish striker Alvaro Morata, who opened the scoring in their 3-0 home win against Lecce on Friday despite starting with a slight knock.

"He (Morata) made a big effort to play the last match," Fonseca said. "He is doubtful and we will manage him. Let's see how he is tomorrow. We don't want to take any risks."