The defender feels that a collective responsibility will be needed to stop the Portuguese attacker, and he also hailed Arjen Robben's class despite recent criticism
At a press conference ahead of Tuesday's first-leg match at home, the right-back underlined the importance to defend as a unit, but admitted that the Portuguese attacker will have his chances.
"You have to defend against him with the whole team," he told Goal.com. However, he admitted: "Individual players can never be 100 per cent turned off."
Lahm nonetheless is confident in his side, and hailed team-mate Arjen Robben, who has taken flak of late for failing to convert a penalty against Bundesliga rivals Dortmund.
"He is a player who can decide games. He has been criticised in recent weeks, but among the team, he is indisputable," Lahm said.
The defender also complimented international colleagues Mesut Ozil and Sami Khedira, who left the Bundesliga for Madrid in the summer of 2010, and have since become integral parts of Jose Mourinho's side. And Lahm feels that in playing abroad, the midfielders have aided in the progress of the German national side.
"Both have gone to Madrid to take the next step, and are part of a great team. It is also important for the national team."
When asked for his opinion on Bayern's chances heading into the Madrid tie, Lahm was coy not to make a prediction, but spoke with confidence.
"I think two top teams will meet each other. I'm not afraid," he concluded.
Kick-off from the Allianz Arena in Munich is scheduled for Tuesday at 20.45CET.