The Blaugrana have not been at their best in recent weeks, but the Dutchman believes that their dip is natural, given their formidable form over the years
In the absence of Tito Vilanova, who is in New York recovering from cancer, the Catalans have stumbled, recording disappointing losses against both AC Milan and Real Madrid in the Champions League and Copa del Rey.
And the Netherlands legend feels they have gone off the boil of late, but remains confident that they will win La Liga thanks to their hefty gap at the top of the table ahead of the Clasico on Saturday.
"I think they lack hunger and other things," he was quoted as saying by Marca.
"That they drop off form at an individual and collective level is normal after playing so many games at such a high level. It's impossible to be as great as Barca have been for so many years.
"Madrid are focused on the game in the Champions League more than the one against Barcelona. The distance between them and Barca is too great and Barca will win the title easily.
"Barcelona have been far from their best. They have lacked a target man because Messi can play a little behind or on the wing. Barca have sometimes lacked these resources."
The Blaugrana have a two-goal deficit to overturn against Milan in the Champions League, but Koeman feels they can do so with a top-level showing.
"There has to be recognition that the 2-0 loss makes it a very complicated task. Barca have to play one of the best games in history to come back from this result."
Barcelona and Real Madrid kick off at 16:00CET on Saturday at the Bernabeu.