The Borussia Dortmund manager has taken responsibility for his 'stupid' behavior in the loss to Napoli, in which he was sent to the stands.
The 47-year-old coach was sent off for gesticulating angrily at the fourth official after Neven Subotic was not allowed to return to the field following a head injury. Klopp has taken full responsibility for his behavior in the loss but believes victory was there for the taking.
Speaking to ZDF, he said: "We did not show our prettiest face tonight, yet we lost with the closest of defeats. We know now that we can beat Napoli, but too many things went wrong, including my red card. It was stupid and I acknowledge that.
"I behaved like a monkey out there. I went too far."
Last year's finalists went behind on a Gonzalo Higuain goal 27 minutes in, with Lorenzo Insigne doubling the advantage midway through the second half before Juan Zuniga netted an own goal three minutes from time.