Slot said: "Trent is not the first and won’t be the last to leave a special club. We did everything we could to keep him and then we have to accept his decision.
"You can maybe understand he wants a new challenge because, if he is so many years in the same league, some players want to experience something else.
"It is a disappointment for the fans, team-mates and for me he is leaving. We are going to miss a very good human being and a very, very, very good full back.
"Conor (Bradley) has such an intense playing style. They all run a lot but Conor is in his own league when it comes to running a lot! He needs time and a programme to keep him fit."