The Colombia attacker has responded superbly to Slot's tactics and system this season.
Slot said, "It's difficult to judge I wasn't here last season and it's still a small sample size. When it comes to us winning a lot of games, everyone we face are bottom half, we expect Man Utd to be nearer top later on in the season. Let's see if we can keep scoring goals if the fixtures get harder and harder.
"Anything specific with Luis? Not really, we try to train a lot and help them in yhe best possible way and how to do things in certain situations but in the last third of the pitch, it is the quality of the player. He has always had this and he scored 8 PL goals last season and with his quality it is not of the standard.
"Maybe he was unlucky but a player of his quality will score goals."