"We tried to win on Friday evening, so we're not happy with the result. Atletico worked for two weeks in preparation for this match and we arrived the day before, so our fitness levels cannot be at their best right now," argued Benitez.
"Douglas Maicon also hurt himself in Montecarlo and will be unavailable for this game. A defeat is obviously not positive, but I am sure the team will react and use it as extra motivation.
"It is going to be a tough campaign and this side always needed a little time to get going in recent years. Our mentality will be crucial."
Benitez has implemented changes from the Jose Mourinho era, taking more risks at the back in order to push forward with greater consistency.
"I don't want a revolution. We're learning gradually what works for us and what doesn't. We also know that at this moment the tactics count for little compared to the mentality and character of the team."