The Cameroon defender was a low-profile summer arrival on a free transfer after leaving Bundesliga side Schalke, and a foot injury kept him out at the start of the season.
Speaking to the press ahead of this week's EFL Cup tie with Derby, Klopp said: "If you lived and worked in Germany you would have known much more about him. It was pretty clear it would make sense to sign him.
"Tall players like him need physical fitness. He needed to create some physical strength, but there was never a doubt about his quality."