Alexander-Arnold struck a superb goal in their 4-0 win on Saturday.
Slot said, "I can talk for hours about that! Unbelievable. I think the biggest compliment Trent could get was the reaction of everyone after the (Manchester) United game. Every player around the world, maybe except for a few, have bad games and that’s completely normal. But the moment Trent has a bad game, everybody has an opinion about him.
"Maybe – maybe – that has to do with the contract situation, I don’t know if that wasn’t there if everybody would have reacted in the same way. The biggest compliment you can get if you have such a great first half of the season and you don’t play a good game against United – that was clear for me, for the fans, for you, for all the analysts who saw the game – (is that) many were quite hard on him, and maybe that’s the biggest compliment you can get."
On Alexander-Arnold regaining confidence, Slot also said: "I do think that is important, but that was not the reason to play him. The reason to play him was that Conor Bradley came back from a hamstring injury and two days ago he played his first minutes against Tottenham Hotspur. I think it’s a bit unknown for everyone how our flight was that night, so we couldn’t land here in Liverpool and we had to go to Birmingham. We came home really, really late and for me it was too big of a risk to play a player that had a hamstring issue five, six, seven, eight weeks ago two days after the Tottenham game.
"Then, the only available full-back is Trent and as a result of him playing I think it was good for him to play again in our own stadium, to feel the reception of the fans again. That was already fantastic when we played Tottenham and also again special for him today. That will only help him and us because if you want to do special things during the season we have to do it together. Not only the players, not only the players with the manager, but definitely the players with the fans."