The Swede was in action, however, the Reds bowed 2-1 to Crystal Palace with the £125million ($167m) striker facing barrage of criticisms for his contribution against the Eagles.
Slot defended the former Newcastle United man as he continues to return to full fitness.
“Isak playing 84 minutes had a lot to do with the low intensity of the game,” he told the media.
"If you face a low block, 10 players in and around their own 18-yard box and when they have to do a build-up they take a while with hardly any intensity.
“In a more open game where you have to run a lot as a nine, then you might not play him for 84, but this was a game in which it was a low block with some bursts of counter-attacks.
“He was close to a goal, very honest to stay on his feet, got a little bit of a shirt pull and that’s why he was unbalanced when he shot. So that was maybe just enough, smart little push to get him unbalanced. He didn’t score but it was quite a good performance.”