Isak went down in pain under a challenge from Spurs defender Micky van de Ven while opening the scoring for the Reds on Saturday night in what was a reckless challenge from the Dutchman.
The Sweden striker underwent surgery on Monday and while there is no timescale offered on the injury, which is likely to leave him on the sidelines for around 3-4 months.
Van de Ven wasn't penalised given the harshness of the tackle, despite many calling for the tackle to be reviewed after it was deemed that the defender lunged into the challenge with little chance of getting the ball.
Speaking on Sky Sports, Carragher has held back from lashing out at the Spurs star, however, claiming that it was just bad luck.
"It's a huge blow because I think Liverpool were actually one attacker short anyway. There's a lot been made about a lot of the challenges in the game from Tottenham players, and a lot of them weren't clever. I've put myself in Van de Ven's position, and that's a challenge I'd probably make.
“He's trying to block it, it's just the follow through. I don't know where else anyone thinks his foot's going to go. He has to make that challenge. You can't let the striker just get a shot away there in that situation. It's just really bad luck for Isak. It's probably one of the first glimpses we've seen of his real quality in a Liverpool shirt."
Isak was sidelined for five games from October to November with a groin injury and his latest setback, which only makes life harder for manager Arne Slot.