The Southampton defender will complete his £75m move on Monday.
After victory over Leicester City, Klopp said: "The really good players will always say that the challenge with other players for a position in the team will always help you. That's how it is. We cannot go in a season with two centre-halves and hope nothing happens.
"The third one is already logical and if you have a fourth one then it's even better. No player should and can play a whole season. At a club like Liverpool, we need to react in situations when a few of them are maybe not at their top level or injured. That's what we did.
"I don't think the boys were nervous, I couldn't see anything like that. They don't have any reason to be nervous because I'm really happy about the development of these players."