"He (Ronaldo) is very pleasant to watch playing. My former colleagues in the Arsenal defense found a very good recipe to stop him," said the former Gunners goalie.

"I will not explain to you now how this recipe works, but I know how you can play effectively against him and I have already spoken to our defender Arne Friedrich about it."

The Manchester United winger scored four goals in Arsenal's net since 2005.

"Ronaldo is a player who can make all the difference," added Lehmann.

Portugal have emerged as hot favorites for this year's title while the Germans have struggled during the group stages.

"This team, unfortunately, has other good players, it is necessary that we are well positioned to avoid letting them get into positions to score goals," concluded the German goalie.