Lando Norris has said former McLaren teammate Carlos Sainz deserved a chance to race for reigning world champions Red Bull in 2025.
On Wednesday, Williams confirmed Sainz will join the team next season on a multi-year deal.
Sainz's future had been the subject of intense speculation since Ferrari confirmed it would replace him with Lewis Hamilton in 2025.
Despite establishing himself as one of F1's top talents, serious interest never materialised from Red Bull or Mercedes, something which Williams boss James Vowles said was a surprise to him given the Spanish driver's record in the sport.
Norris agreed, and said Sainz deserved to stay at a front-running team.
"The easy one is just to say Red Bull. He should have gone there, in my eyes," Norris told Sky Sports when asked where his friend should have gone.
Sainz has won three F1 races since joining Ferrari in 2021 after two seasons alongside Norris at McLaren.
Despite serious questions over Sergio Pérez's spiraling form Red Bull never showed serious interest in Sainz, who started his career with the company's junior team Toro Rosso (now RB).
Pérez was given a contract extension for 2025 despite not being on the podium since April's Chinese Grand Prix.
Norris added: "Obviously I'm biased, I know Carlos a lot more than I know Checo [Pérez] and that kind of thing, but Carlos deserves a lot. He's one of the best drivers in Formula One, he's proven that countless times, and I'm a good friend of his.
"I'm happy for him that he's still in Formula One and I'm happy he's got a drive and can try and bring Williams back up. Him partnering Alex [Albon] will be good for Formula One at the same time.
"That's a good thing. But I'm sure a lot of people would love to say he should have gone to Red Bull, potentially, but that's not my decision to make."
On Monday, Red Bull boss Christian Horner told employees gathered at the team's factory that Pérez would stay on beyond the F1 summer break.
There had been speculation Pérez would be replaced before the Dutch Grand Prix but that has not come to pass.