The 26-year-old barely trained throughout the summer as he went on strike in order to force his move from Newcastle to the current Premier League holders.
Isak finally got his British record move in the last couple of days of the transfer window, and has struggled to find his form since, scoring just once in his six appearances across all competitions.
Daily Mail reporter Lewis Steele, who covers Liverpool, has since revealed that it could be another three months before he’s back to full fitness.
Speaking on his vlog, he said: "The road to full fitness is a little bit longer than expected, and there’s a report from one of the Newcastle guys, saying they expect it to be three months until he’s fully fit. And that is probably about right.
“He’s been at Liverpool now for four or five weeks, so maybe we are now probably another three or four weeks away from seeing Isak at his best.
“There have been glimpses, lovely assist on Saturday and he got his goal against Southampton, to be fair he’s got to score that, but he had to be in the right place at the right time.
“But, the road to full fitness does seem a bit bumpier than me or Slot predicted. But, as I said with Salah, if he gets a bit of confidence, it should be all good."