Boateng: Ronaldo is a machine, he finishes chances with his right, left and head Champions League - Bayern vs Real Madrid The No.7 is the tournament's leading scorer

Real Madrid head to Bavaria for their Champions League semi-final against Bayern Munich in the knowledge that they'll need Cristiano Ronaldo to be at his best, and Jerome Boateng has labelled the forward as a machine who can finish chances perfectly.

Jupp Heynckes has been spreading a message to his team that focus will be vitally important against Real Madrid, especially if they are to keep out a forward who has found the net in every single Champions League match this term.

"Cristiano Ronaldo is like a machine, he finishes with his right foot, left foot and his head, all perfectly," Boateng explained in an interview with Kicker.

"No forward is as complete as Cristiano Ronaldo.

"You can't keep him completely quiet, he always manages to have chances in a match."

Boateng has faced the Portuguese international on multiple occasions, both at domestic and international level.

"I have both positive and negative experiences with him," he admitted.

"With the national team we've always managed to silence him, for example the 4-0 at the 2014 World Cup.

"With Bayern we've eliminated Real Madrid once, but we've been eliminated ourselves twice."

The difficulty the German champions have is that in attempting to watch the former Manchester United forward closely, they lose some focus with regards to the other talented attackers in Los Blancos' squad, something which Boateng is acutely aware of.

"If you take him out of the game, you've still only done 50 percent of your job," he confirmed.

"Real Madrid's other players are all so good."

The first leg at the Allianz Arena kicks off at 20:45 CET on Wednesday evening.