The La Liga match was originally scheduled for 26 October but was postponed because of fears of civil unrest in Catalonia.
Both sides are level on 35 points but Barca top the table on goal difference.
“In games like this you’ve got to produce your best throughout the 90 minutes,” said Zidane.
The game has been delayed by two months after days of protest took place in Barcelona as nine Catalan separatist leaders were convicted of sedition over their role in the referendum and handed jail sentences of between nine and 13 years.
La Liga made the postponement request because of “exceptional circumstances beyond our control” as more protests were expected in Barcelona on the day of the match.
Both clubs disagreed with calls to switch the game to Madrid, but will share the same hotel in the lead-up to Wednesday game and travel at the same time two hours before kick-off amid security concerns.
Zidane said: “That’s something different for us. We’ve been told that we have to leave together and that’s what we’ll do.
“There’s nothing else to explain. The important thing is that the game goes ahead.”
Barcelona head coach Ernesto Valverde added: “I think we could have played the game on the original day and there is no reason why we can’t play the game tomorrow.
“It is unlikely in a situation like this that the players will meet before the game, so I probably won’t see Zidane, but I have a lot of respect for him.”
Match stats
Head-to-head
- Barcelona have won more La Liga games against Real Madrid than any other side (72), while Real Madrid have beaten Barcelona the most often in the competition (72).
- Barcelona could record more league wins than Real Madrid for the first time in El Clasico history.
- Barcelona are one goal away from reaching 400 goals in the fixture in all competitions and just four goals away from equalling Real Madrid’s total of 403.
- Real Madrid have gone six La Liga meetings without winning against Barcelona (D2 L4), their worst such run in El Clasico since December 2011 when they had seven.
Barcelona
- Lionel Messi has failed to score or assist in his last three games against Real Madrid in all competitions. The Argentine has never gone four consecutive appearances against them without scoring or assisting.
- Luis Suarez could become the third Barcelona player to reach 10+ goals against Real Madrid in La Liga history, after Lionel Messi (18) and Cesar Rodriguez (12).
- Sergi Roberto has provided six assists in eight appearances against Real Madrid in La Liga, with five of those assists resulting in Luis Suarez goals. They have combined for more La Liga goals in El Clasico than any other duo in the 21st century (five).
Real Madrid
- Real Madrid captain Sergio Ramos has the chance to become the player with the most appearances in El Clasico history (43), surpassing Manolo Sanchís, Francisco Gento and Xavi (42 each).
- Zinedine Zidane is unbeaten in his four managerial games at Camp Nou in all competitions (W2 D2) and he could become the first Real Madrid manager to remain unbeaten in five away Clasicos.