Massimiliano Allegri feels Milan need to perform as a team if they are to knock out Tottenham on Wednesday night.
Milan are 1-0 down on aggregate after losing the first leg at San Siro last month.
"We can do it because we have a strong team which is physically and mentally fine," Allegri said.
"The first leg was a strange game. We know that Tottenham are a strong team and we mustn't commit the mistakes that we made at San Siro.
"Tomorrow's match must be one of Milan and not of individuals. If we don't play as a team, we'll find it difficult to get a result.
"There are several solutions for the formation tomorrow. We can play with Thiago Silva in midfield or in defence. I have various solutions in mind and I will judge them today.
"It will not be a historic exploit if we go through. We are talking about overturning a result that in the first leg was a lie.
"It will be a different game at their home with respect to the first leg, but we must play a game of great intensity, of great sacrifice and of great technique."