The Reds ended a highly-publicised protracted transfer saga by sealing a deadline day raid on Newcastle for the Sweden marksman, paying the Magpies a British record 125 million pounds for the 26-year-old.

But having missed the majority of the pre-season trying to force through his dream move, Isak has been made to pay a very heavy price.

Indeed, for a player who relies heavily on his fitness and making sure he follows a strict programme, the 25-year-old arrived on Merseyside immediately playing catch-up, having not started a game since May 25.

And while Liverpool have done their best to try and manage his minutes and help build up his fitness, he is yet to complete a full 90 minutes for the Reds and has only played 70 minutes or more twice under Arne Slot so far.

Now, after his latest cameo for his country - a demoralising 4-1 defeat to Switzerland on Saturday - Isak has conceded that the season has been a major disappointment for him so far.

"It was about half an hour. It felt okay," he told Sportbladet. "I feel like the reaction was good after the match in my body.

"Hopefully I can play properly in the next match (against Slovenia on Tuesday). It's always frustrating when you're injured.

"Regardless of whether it's one match or more. It's always worst for the player himself.

"It hasn't been optimal. But when I'm on the field, I don't give myself any excuses. I always want to play my game and perform.

"But yes, it's hard to be away and not be able to help and contribute. Now I'm back and I'm positive.

"There's not much that's easy in football. But with experience, you learn to deal with things. That's how it is with injuries and all that. You learn to deal with it and get back on track the right way."

Now, a deep dive into fitness track record suggests it will now be next year before Liverpool get to see their club record signing firing on all cylinders…

Since signing for Liverpool on September 1, Isak has missed six of Liverpool's 14 games played since then (42.8 percent).

In those eight appearances, which total just 391 minutes of action so far (at an average of 48.875 minutes per outing), he has scored just one goal.

Yet, Liverpool should not be surprised by his fitness issues, and a delve into the archives shows that he has suffered with a number of injury niggles during his time in the game and, in particular, since first arriving at Newcastle in August 2022.

During his time at St James' Park, Isak missed a total of 32 games through various issues, the most serious being a thigh problem that forced him to miss 107 days between September 2022 and January 2023.

On each occasion, he was eased back in. And while ultimately returning to form, the fact that he is now easing his way back after what's described as adductor pain will likely mean Liverpool will need to continue monitoring his minutes carefully through the rest of this month and into December.

Slot will also be acutely aware that another minor setback could push the striker back further on his road to full fitness, and it's now been 176 days since the striker last played a full 90 minutes.

Sweden boss Graham Potter also admitted having to carefully use the striker during the international break, with Liverpool keen observers of their striker's performance.

"He's had a good week, he's available," Sweden manager Graham Potter said before Saturday's match.

"But we have to be smart with him because he's been out for a while. He's not ready to play two matches for 90 minutes. We have to wait and see until tomorrow," said the former Chelsea, Brighton and West Ham boss.

Since that 4-1 defeat, Potter revealed that Isak is likely to get more minutes on Tuesday as Sweden face Slovenia in their final World Cup qualifier.

"The plan was for Isak to play 30 minutes," Potter said post-match. "It wasn't an easy position in the game to get into.

"Hopefully, we'll see more of him on Tuesday."

Pep Guardiola 'more focused' on Manchester United FA Cup final