The Liga champions' director of institutional relations believes they have what it takes to beat their arch rivals in the second leg on Wednesday
Los Blancos went 1-0 up in the 55th minute courtesy of a Cristiano Ronaldo header, but goals from Pedro, Lionel Messi and Xavi helped the Catalans to a seemingly-comfortable 3-1 lead.
But Angel Di Maria pulled one back in the closing stages thanks to a Victor Valdes error to make sure the tie is still wide open, and Butragueno is confident Madrid will eventually come out victorious.
"All the players are mentally prepared for these matches. The Spanish Supercopa can still go either way," the 49-year-old was quoted as saying on the official Madrid website.
"It will be a very attractive second leg and I'm sure we'll be able to win with the fans' support, and give our supporters more cause for celebration."
The second leg takes place at the Bernabeu on Wednesday evening, and is scheduled to kick off at 22:30CET.