Slot this morning is celebrating winning the Premier League at first attempt as Liverpool manager.
And fellow Dutchman Zenden told BBC Radio today: "For him to make the move to the Premier League, especially to a big club like Liverpool into the footsteps of Jurgen Klopp, I think no one expected him to actually do what he did with his staff and his players.
"In the beginning people were thinking someone’s coming in from the Mickey Mouse league, what’s he going to do at Liverpool?
"But very soon he turned around the criticism with beautiful football, with charisma and I think everybody now sees what he’s capable of doing and the most interesting thing is probably still to come.
"I’m sure he’s not going to sit still. It’s strange to talk about when you’ve just won the league but I’m sure that in the back of his mind he’s already planning for next season."