Klopp spoke with ESPN Netherlands about the Dutch coach.
"We spoke one or two times (at the start)," Klopp said. "I think we texted a few more times. But there is nothing I can tell him what he couldn't know himself. Right now from my side, just to give positive feedback in the beginning because we are all human beings and he worked his socks off.
"I know that because the tour is super intense in a year when you have Euros and Copa, you don't have the team together, but they come, you have one week until the first matchday and stuff like that.
"So I think he had similar situation, but exactly the same situation? Definitely not. When I saw the games, that's why I watched it, not to think, oh, how does it look? The work he did was obvious, the ideas obvious. And that's the best you can say about the coach.
"I was really happy when I heard that Liverpool was going for Arne Slot. I wasn't involved in anything, it should not be like that, and I'm not this kind of guy in the background, still having some strings and stuff.
"Like I don't want that. The club is too big, too good. People are too good. A lot of things changed since we left. But the only concern for me was, will they get a good coach? Liverpool was early and Liverpool got a top, top, top solution in Arne Slot."