Milner, 30, spent most of his career in midfield but has impressed in a new defensive role this season, playing 16 Premier League games to help the Reds to second place in the table.
Klopp revealed the former England international was a player he always wanted to have a space for, praising his flexibility.
“Football has changed in the last few years and you need different players with different skills for different positions than before,” Klopp said ahead of Saturday’s crunch home match against title rivals Manchester City.
“For us, it was clear that if Millie was open for this position then everything would be good.
“It was not a big surprise for us – not because we are geniuses, only because we already knew him and knew how we wanted to play from the position.”
Klopp does not feel the change from a winger to a full-back is any different to defenders like right-back Nathaniel Clyne working to improve their skills going forward.
He added: “Clyney, on the other side, played the position in the past completely differently.
“Now he is the same on the right-hand side. He is more a winger than he was last year. That is exactly the same development, only a different way.
“Things change and players have to adapt. You are never too old to develop. Millie didn’t love the position but I think nobody really spoke with him about it, ‘Put him there and play’.
“We always liked this player and for us it was clear we would try everything to use him and that is what has happened.”
