"If I have one wish this Christmas, it would be that he recovers well and as quickly as possible," Slot said in a Christmas message on Liverpool's website.
Isak injured himself when he scored against Tottenham.
"The fact that we will not have Alexander Isak with us for some time to come is, of course, a big disappointment. The moment Alex was injured, he showed the mobility, finishing technique and overall quality that he can bring to our team, so it is a hard blow to be without him," Slot continues.
The coach also sends his thoughts to Diogo Jota's family, who are celebrating their first Christmas since the Liverpool player died earlier this year.
“I can only hope that the feeling of love and affection that Diogo still evokes gives them some comfort.”
Liverpool face Wolverhampton on Saturday. It is the first time the clubs, both of which Jota played for, have met since the Portuguese's death.
"The sense of loss will be particularly strong on Saturday. Like us, Wolves were clearly deeply affected by the loss of such a special player and person, and my thoughts continue to be with them as well."
