Hamilton's move to Maranello displaced Carlos Sainz, who has spent most of 2024 trying to find an alternative team despite bringing home two victories for the Scuderia.
Finally, in the summer, Sainz signed a long-term deal with Williams, in a shock move having been previously linked with Mercedes, Aston Martin, Red Bull and Sauber ahead of their transition into Audi.
Unlike Hamilton, whose Ferrari debut is set to be delayed due to Mercedes sponsor duties, it has now been officially announced that Sainz will make his Williams debut before the year is out.
The end-of-season tyre test will take place in Abu Dhabi following the conclusion of this year's championship, with teams taking the opportunity to gain valuable data from the session.
Sainz will be suited up in his new Williams attire, taking to the track just days after ending his Ferrari partnership.
While Hamilton will not be present, a plethora of other drivers are set to take to the track at the Yas Marina Circuit with their new teams in the test, including Alpine-bound Jack Doohan, Mercedes' Kimi Antonelli and future Haas star Ollie Bearman.