Jens Lehmann claims he is in possession of a secret 'recipe' that will dramatically reduce the impact of Portugal's star man Cristiano Ronaldo.

Germany face Portugal in the Euro 2008 quarter finals on Thursday and, as always, it is Ronaldo who will the focus of Joachim Low's concerns after a tremendous season with Manchester United in which he scored 42 goals.

His record against Arsenal reads 4 from 11 games and Lehmann feels the North Londoners have cooked up an effective strategy to deal with one of the world's finest players.

The keeper, who is set to join Stuttgart on July 1, has now been stirring things up by spreading his secret formula amongst his Germany team-mates.

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

"He is very pleasant to watch playing, but my former colleagues in the Arsenal defence found a very good recipe to stop him.

"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."