Despite only lasting three months, the deal felt like years of speculation and fresh twists by the time it was signed off - which isn't actually too far from the truth, even if fans didn't know it.
Liverpool's former sporting director, Michael Edwards, returned to the club in 2024 as the ownership group FSG's chief executive of football.
That followed a two-year absence after Edwards had initially joined the Reds in 2016 and oversaw the transfers of pretty much every star Anfield has seen in recent years.
One player the director reportedly missed out on the first time around, though, was Isak.
It's easy to forget that back in 2016, the Swede was breaking into senior football and became widely regarded as one of Europe's 'next big things' at AIK - his career didn't quite pan out as planned immediately after that, but he got there eventually, regardless.
His stock was so high that Liverpool and Edwards reportedly held a meeting with Isak's representatives to discuss a move to the club, according to Swedish outlet Matchdax.
The report claimed that Liverpool came close to signing the then-youngster, but a move never materialised and Isak instead headed to Dortmund in January 2017.
Fast forward to 2022, and the Reds once again had the opportunity to sign the Swedish international.
Liverpool's former Director of Research, Ian Graham, told the Financial Times that then-manager Jurgen Klopp had opted for Darwin Nunez over Isak.
"In 2022, (Klopp) signed Darwin Nunez instead of Alexander Isak," Graham told Financial Times.
"Both players, if you look at the top young centre-forwards in Europe, they would be number one and two - or two and three but (Erling) Haaland was going to Manchester City and out of our price range."
As we all know by this point, Isak was snapped up by Newcastle and in the summer of 2025, Nunez left Liverpool for Al Hilal after a mixed couple of seasons in England.
The Uruguayan was eventually replaced by none other than Isak, a transfer nine years in the making.