Bayern Munich midfielder Javi Martinez has insisted that the German outfit will have to be at their best to overcome Real Madrid in the semi-finals of the Champions League.

Bayern travel to the Bernabeu for the first leg of their last-four clash on Wednesday, before the pair meet in the reverse match next week.

"We'll have to control the counter-attacks they generate," he told reporters.

"They're very fast on the counter. They have very fast players who mount their counter-attacks against you and can score goals. That's what we'll have to be most vigilant about."

Martinez was a regular opponent of Madrid during his time with Athletic Bilbao.