Las Palmas go to Real Madrid on Sunday, having won three out of their last four games.
Martinez said, "We are facing one of the best teams in the world, in terms of sporting potential, economic potential and titles. Let's not forget that they are the current European champions. The challenge is difficult, but it is easy to explain: We have to play our best game, be totally accurate and they have to not have their day.
"It is a game to have the ability to do any action, even if it is in the opponent's corner, in two seconds the ball will be in your area. The key is the mentality for 90 minutes and extra time.
"In today's football there is a tendency towards transitions, high speeds and one-on-ones. Real Madrid are specialists in this type of action.
"We have to stay together, not leave spaces and cover the outside shot because they are being effective. We have to be aware that we have to defend very well and be effective when they leave spaces."
He added, "It's never a good time to play against Real Madrid. It's like facing Mike Tyson. But we're going to do it with maximum conviction to get the three points. We're going to try to knock out Mike Tyson."