The Santiago Bernabeu director believes the Serie A outfit will prove to be a very difficult opponent for Los Blancos in the Champions League last-16
Madrid were paired with Napoli after finishing second in their group behind Borussia Dortmund, and Butragueno has warned Maurizio Sarri's men are a force to be reckoned with.
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"Napoli have a very good coach and have improved a lot in recent years. They will be very difficult opponents," Butragueno told reporters.
"We know that the Italian teams compete very well. They are used to withstanding pressure, playing tight and they play very well in these situations. We have to be very careful because it is sure that they will be a very dangerous opponent.
"For them it will be an extraordinary motivation to come up against Real Madrid.
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"We are going to have the first game at home and we have to get a good result. The second leg is away and we know what the atmosphere will be like in their stadium.
"At home we have to be very solid, get a good result to take us to the draw for the quarter-final."