Liverpool boss Jurgen Klopp has explained not moving for Mats Hummels.

The former Bayern Munich defender returned to Borussia Dortmund this summer.

Klopp and Hummels won titles together at BVB and the Reds manager says: "We have always kept in touch. He is a natural leader.

"He is the best German central defender. I was happy about his return to Dortmund. It just fits.

"For me, this is a very logical story, that in such a long career as Mats will have had at the end, he stays away for three years and goes to a club where obviously you can still win titles - and he comes back to his original place."

Asked if he tried to sign Hummels, Klopp added: "No, because we already have four world-class centre-backs."