Bayern Munich had a 3-1 lead but they threw it away in the closing stages of the match.
“I’m deeply disappointed, and angry too,” Klinsmann told Bayern’s official website.
“We’d basically wrapped it up at 3-1, but we were negligent and carelessly tossed it away.
“It gnaws at you, I had a restless night. It hurts, but I’m a born fighter. I know what the problems are. We’ll talk them through and remedy them step by step.
“We’ll talk to the team about them today and we won’t mince our words.”