The Brazil international made a transfer request on Friday to join Barcelona but it was instantly rejected.
“I had to sell a lot of players in my managerial career," Klopp said.
“Some had clauses, some had no clauses. We had the (Robert) Lewandowski thing and that was difficult when he went to Bayern on a free transfer. A lot of different things.
“The only thing I can say about this is that in life everything is about timing – whichever club asks early enough.
“It's like how we try to do it. If we ask early enough, we try to do it. If you ask early enough, you can either switch the plan of whatever. But you cannot come up, close to the start of the season and things like this.
“It's like I said: the club is bigger than anybody. That is the most important thing. It's about doing it in the right moment. It's how we do it when we want to bring players in.
“Most of the other clubs won't come to us and say 'by the way, we have a good player, do you want to buy him?'
“It is about timing. That is how I understand it. And that is all I have to say. Maybe everybody has a price – in the right moment. In the wrong moment? No price."
Liverpool's position is unchanged in the wake of the transfer request which was sent by Coutinho via email to sporting director Michael Edwards.