The Basque giants face off with Los Blancos in Riyadh as Muniain and co aim to defend their title in Saudi Arabia.
“We played two games in December against them and lost both,” as per reports from Diario AS.
“But they were very close matches, with many chance for us to win.
“It’s clear Real Madrid are favourites. But, last season and again this season, we were the least fancied for the title, but once the ball rolls, what you do and how you perform in 90 minutes, decides the result.”
Athletic Club qualified for the 2020/21 competition on the back of winning the 2019/20 Copa del Rey in the second season of a four team format.
A 3-2 extra time win over Barcelona secured their first Supercopa title since 2015, with Inaki Williams’ goal proving the difference, as Marcelino clinched an immediate trophy following his arrival in Bilbao.