Former Real Madrid defender Fernando Hierro has warned Los Blancos about the danger of Schalke 04 ahead of the first leg of their last-16 clash in the Champions League.
The Spanish outfit have won just once on their last 25 visits to Germany, but Hierro has backed his former side to advance from the two-legged affair.
"The key is the competitive nature of German football. German teams never try to leave the door open. They are very demanding, always playing up until the last moment," he told Goal.com.
"It is always difficult to play in Germany. You never know what will happen and, as Schalke have reached the second round of Champions League, they're rivals to the best teams in Europe.
"But Real Madrid are in fantastic form and I think they have a lot of confidence and this is a great time to eliminate Schalke from the Champions League."
Hierro spent 14 years at the Bernabeu.
