Heynckes, Lahm insist teamwork is key
Real warmed up for the first leg in Munich with a 3-1 win over La Liga strugglers Sporting Gijon on Saturday, when Ronaldo scored his 41st league goal of the season. It is a record achievement currently matched only by Barcelona's Lionel Messi.
Ronaldo also netted his 100th Spanish league goal in Real's 5-1 win over Real Sociedad last month, making him the quickest Real player to reach his century, in 92 games. He broke Ferenc Puskas' previous mark of 105 matches, which the legendary Hungarian forward set in the 1960s.
Portugal star Ronaldo has scored 59 times in 55 games for club and country this season, but Lahm says taking on a player of his stature and reputation is something for any professional footballer to relish.
"You have to have a lot of respect for someone like him, especially after what he has achieved," said the German captain. "I know what he has had to do to reach that level, you have to work really hard and he is the sort of player you want to play against and compare yourself to."
The Bayern right-back will be tasked with containing Ronaldo down his flank, but the 28-year-old German insists it will be a team effort.
"I think you have to talk about the whole team, we need to work together, stand together and be organised and then you have the chance to nullify a player like that, but things can happen fast," said Lahm.
"You can't eradicate any single player, besides we have players like [Arjen] Robben, [Thomas] Muller and Toni Kroos they will need to worry about."
Bayern coach Jupp Heynckes, who coached Real to the 1998 Champions League title, said Bayern can ill afford to worry about just one player. "Ronaldo versus Lahm sounds good to an outsider, but if you study Real, [Karim] Benzema also plays well whether on the wing or the middle, same for [Gonzalo] Higuain," said Heynckes.
"It isn't just Philipp Lahm's job to stop Ronaldo, it is the whole team's responsibility. And I will show the team what they need to do to stop him as a group."
Lahm: Fight until the last minute
Bayern have never been beaten by Real in Munich in their nine previous meetings in the Bavarian capital, but Lahm says history will count for nothing come kick-off.
"That is the past, they will try everything and they will have chances," he said. "Our job is to go for it, we will have to give a great performance and fight from the start. It is two or three little situations which can win the game, we will do everything we can, but even if we don't win at least a 0-0 will be something."
"It's a mix, you have to defend well, it would be great if we don't concede a goal, but as a defender you have to try and go forward too. It's important we are aggressive and we fight from the first until the last minute."