TENERO, Switzerland (AFP) - Germany's ex-Arsenal goalkeeper Jens Lehmann says he knows a secret recipe to contain Portugal's chief play-maker Cristiano Ronaldo ahead of Thursday's Euro 2008 quarter-final.

"Ronaldo is a player who can make all the difference," said Lehmann, who has signed a one-year contract to play for VfB Stuttgart next season.

"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."

Lehmann stressed 23-year-old Ronaldo, who was again voted the Premier League players' player of the year for the second season running, was not Portugal's only attacking weapon.

"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," said Lehmann.

Should Thursday night's game in Basel be decided by penalties, Lehmann says he expects to be handed a detailed analysis of where the Portuguese players like to hit their spot-kicks prior to the game.

The German goalkeeper famously read notes on a piece of paper in the 2006 World Cup quarter-final penalty shoot-out with Argentina just prior to facing the South Americans' spot-kicks to intimidate his opponents.

The move paid off and Germany went through 4-2 on penalties.

"I do not know where I will put this piece of paper, maybe I will slip it into my socks," he smiled.

"But I hope we will have secured victory before we come to a shoot-out."