Casillas: Marseille biggest test so far
Casillas told Spain's Marca daily on Monday the Group C clash would have added spice as Marseille's former Real pair of defender Gabriel Heinze and striker Fernando Morientes would be anxious to impress on their return to the Bernabeu.
"They will want to play a great match, I have no doubt about that," Casillas said.
"It will be special for them for sure as coming back to the Bernabeu after spending many years here is something that cannot fail to affect the emotions.
"I wish Heinze and Morientes all the best because we had some good moments together."
Real have a perfect five wins out of five in La Liga this season and comfortably won their opening Champions League match at FC Zurich 5-2.
The final of Europe's top club competition is at the Bernabeu in May but Casillas said it would be wrong for the players and staff to focus too much on reaching it.
"For sure the atmosphere (for the final) will be amazing but we can't obsess about it," he said.
"Madrid is always aiming to win the Champions League because it's the competition that has given us the most glory and history but we can't be thinking we are going to win it at home. There are other very good sides."