The veteran centre-forward is off contract next month and keen to return to Europe.
Klopp told Sportbladet, "If he had not played for Manchester United before, then we might have considered him.
"No, but I'm not even sure he wanted to play here. We're a pretty intense team haha ... With that said, I couldn't have had more respect for Zlatan.
"I love his whole career, love his efforts, love his confidence. While it may not always be right, it is entertaining anyway. He's a fantastic character and I really hope he doesn't stop playing football. The world will miss him too much."