The former Juventus man came off the bench in a 2-1 win against Southampton in the Carabao Cup quarter finals.
The Reds won on Wednesday, with Chiesa making a positive contribution from the bench.
Slot stated post-game: “I don't know if we saw it the same, but I think what I saw is what you can expect. If a player is out for five or six months you cannot expect (too much). I saw ups and downs. I saw some really good moments and I saw some moments where I felt like, 'OK, you can do better than this.'
“For me, that's completely normal if a player has been out for so long and plays his first game in five or six months.
“I already said before that it makes it so difficult for me because normally in the pre-season a player gets three, four or five games especially and then he's only out for four or five weeks. Instead, he was out for so long, so to get him back to his best level is not easy, but it was good to see that he showed some quality already today.
“But it's the same for him like the youngsters, it's not enough to play at this level, you have to compete with Mo Salah, Cody Gakpo, Lucho (Luis Diaz), Darwin and Diogo (Jota). But it's good to see that he's back and that he had a few good moments in the game.”