Hansi Flick wants Barcelona to approach the Supercopa de Espana final in the same manner that they did their semi-final, rather than focusing on Real Madrid's qualities.
Barcelona made history in the semis, recording a resounding 5-0 victory over Athletic Club, the biggest victory in the competition's history.
It was also the first time three different players have been involved in three goals in a single game in the competition, since at least 2010-11, in Fermin Lopez (one goal and two assists), Raphinha (two goals and one assist) and Roony Bardghji (one goal and two assists).
Barcelona have won a record 15 Supercopa titles and are the defending champions, having beaten Madrid 5-2 in last year's showpiece match.
Ahead of Sunday's rematch between the old rivals, Flick said: "It's the Clasico, and I want to see the same thing as against Athletic Club.
"That we play as a team, united. That's what I want to see. I want them to show me their best on the pitch. For me, that's the most important thing.
"Madrid are a fantastic team, one of the best. They have world-class players of the highest quality. But I'm focused on my team, because we want to win this title.
"The most important thing is the team, not who plays or what position they play in."
Barcelona are the favourites to clinch the title for a record-extending 16th time on Sunday, with the Opta supercomputer giving them a 44.4% chance of victory.
However, Madrid have a 30% win likelihood and will be full of confidence, having beaten Barca 2-1 in the Clasico when the sides met in LaLiga in October.
"A final is a final, and a match against Real Madrid is completely different," he added. "I don't want to hear any talk about favourites.
"What we want is to put on a great performance and play good football.
"We're focused on the match, and I trust my players to do well. We'll try to give our best version to win.
"It's just one match. Afterwards, we'll be back competing and focusing on whatever comes next, whatever the outcome of this Supercopa.
"But, of course, we want to win, because it will give us confidence. My team is very focused, and I'm very happy with what I'm seeing from them."