Liverpool were beaten 4-2 on Saturday, with Slot admitting some of his players were fielded out of position.
He remarked afterwards: "I saw a few good things but I think we also have to improve in certain areas. We got counter-attacked too much today, but that probably also has to do with the fact that we missed out on seven senior players and we wanted to give 20 players playing time.
"As a result of that, too many players didn’t play in their own position. But we still were able to play our normal game, but we were a bit too open once in a while on the counter-attack."
Slot let Luis Diaz out of the matchday and admitted the decision was made with an offer from Bayern Munich on the table.
He continued: "In Lucho’s situation it was, yeah. There’s a lot of rumours around him lately and I cannot go into that. He’s training really well with us but we have decided for now not to play him yet. In Darwin’s (Nunez) situation he has trained also really well and played a few good games for us already this season. But he was injured so we didn’t take the risk.
"Like I said, Lucho is training really well and we’ve decided that he’s not playing at the moment in the games. I cannot comment much more about that."