The 22-year-old was one of the hottest properties in the attacking market in the transfer window after shining for Spain at Euro 2024, where he and Barcelona prodigy Lamine Yamal terrorised defences in Germany.
Williams scored twice - including in the final win over England - and set up one more during Spain's run to continental glory, which came on the back of an equally terrific domestic campaign.
No player registered more assists than the 22-year-old in the 2023-24 campaign - 14, level with Alex Baena of Villarreal - while he also chipped in with eight goals of his own in all tournaments.
Now boasting 20 goals and 26 assists in 126 appearances for Athletic Bilbao across all competitions - in addition to one Copa del Rey - Williams is still contracted to the Basque side for another three years, having signed an extension back in December.
Williams: 'I always wanted to stay in Bilbao'
That renewal reportedly includes an affordable release clause of around £48m, and all of Arsenal, Chelsea and Barcelona were reported to have been battling for Williams's services over the summer.
At one stage, it appeared that a move to Camp Nou was on the cards, as if Williams was to leave Athletic in the summer window, he reportedly wanted to stay in Spain rather than move to England.
However, the deadline passed without Williams securing a big-money switch elsewhere, but in a recent interview with DAZN, the 22-year-old insisted that he was never considering a move elsewhere.
Williams did not close the door on a switch at some point further down the line, though, saying: "It's always good when big teams want you. But I always said that I wanted to be here.
"If there was anything, it was from my agent. I wanted to play in Europe with Bilbao [this season]. My heart is Bilbao, but nobody knows what will happen in the future."
Despite his stellar feats last season and for Spain at the Euros, Williams is yet to score or assist in the 2024-25 campaign, although he has only started two of his side's four La Liga matches.
Which club needs Williams the most?
With Williams refusing to commit the remainder of his playing career to Athletic, tongues may be sent wagging over a possible move in 2025, but a move to Chelsea should be ruled out straight away.
The Blues have wide options coming out of their ears at the moment, and with Jadon Sancho set to join permanently next summer following the 2024 arrivals of Pedro Neto and Joao Felix, Williams is far from guaranteed regular starts in West London.
It may be a different story at Arsenal and Barcelona, though, as the Gunners do not have an option to make Raheem Sterling's loan permanent and may not be banking on a long-term association with Leandro Trossard, who turns 30 in December.
Meanwhile, the Barca wide ranks will be thinned if Raphinha and Ansu Fati leave next summer - both men have been frequently linked with exits in the past year.