Keita again featured for the Reds in their friendly win at Tranmere Rovers yesterday.
Klopp told liverpoolfc.com: "I would really be a little bit too long [talking about] why I like him. He was two years ago, together with maybe Thiago Alcantara of Bayern, for sure the best player in the Bundesliga by far.
"It was unbelievable how he played and then we wanted to get him in, but Leipzig didn't think that was the best idea in the world so they kept him. And then last season was good but not as good as the year before, but it was still good.
"He is young, he is full of football skills, very stable, very good in small spaces, endurance-wise fantastic, quick, good finishes, good runs in the box. So that's a package that's really interesting and that's why we thought we should take him."