Seedorf's men face a stiff task at Vicente Calderon on Tuesday after suffering a 1-0 defeat in the first leg of their last 16 tie at San Siro last month.
Milan occupy a mid-table position in Serie A and will be underdogs against an Atletico side that sits second in La Liga following an impressive campaign to date.
Yet former Netherlands international Seedorf is hopeful his team can put their own disappointing domestic form behind them and progress to the Champions League quarter-finals.
"I've often been in situations in which we're not the favourites, even in years in which we achieved important things," Seedorf said.
"The favourites were and are Atletico Madrid. I think the two sides will play in a similar manner to the first leg.
"They have a narrow advantage - the game is open and I'm expecting changes with regards to the first leg.
"We have to fight as a team and play with our hearts. These things come before the technical and tactical aspects.
"Our approach will be similar to the one in the first leg. We will be aggressive and try to score
"Milan have a great history, and we have to honour the club and the shirt.
"The players are also extremely motivated. It's an important moment for everyone - we know we can write a beautiful page in this club's history."
