Real Madrid are viewed by many as the favourites to triumph at Camp Nou, with Barcelona having their problems in the early stages of the 2021-22 campaign.
However, when asked about the strength of the squads, Koeman insisted that his set of players is just as impressive as Real Madrid's.
"I don't know, although there is a difference in terms of experience. We also have some experienced players. So it's close. There are some areas where they might be better and some where we might be better," Koeman told reporters.
"We'll try to play to our best. I don't think there's a favourite for this game. Possession is important for us, while they play well on counter attacks. We'll have to be well organised when we have the ball and when we lose it, to control their counter attacks."
Koeman's future at Camp Nou continues to be called into question, but Barcelona have now won their last two games against Valencia and Dinamo Kiev respectively in La Liga and the Champions League.