Former Real Madrid striker Javier Portillo says they must careful tonight against Napoli.
Real host Napoli in their Champions League tie with several absentees due to injury.
Portillo told TMW: "I expect a very balanced and hard-fought game. Real Madrid must not make the mistake of underestimating Napoli, because despite always starting as favourites when they play at the Bernabu and in the Champions League, they arrive at this match with numerous and heavy absences.
"Real Madrid must always compete for every goal, its history says so.
"The Blancos must always be ready to win, be it the championship, the Champions League or any other competition."