Valtteri Bottas' move to Alfa Romeo has officially been announced after months of speculation over the the Finnish driver's future in the sport.

Bottas, who has been racing with Mercedes for five years, is set to join the Italian team on a multi-year deal replacing the retiring Kimi Raikkonen, while young Briton George Russell is expected to be announced as the new Mercedes driver to partner Lewis Hamilton in the coming days.

Bottas is expected to be the first of many signings as silly season begins going into the second half of the season. With just 20 seats at the highest level of motorsport, driver changes are a frequent part of the sport, with 2021 proving to be no exception.

With Russell seemingly on his way to Mercedes at the conclusion of this season, in one of the worst kept secrets in the paddock, a new seat will be open at Williams going forward.

The British constructer, who have spent most of the last few years at the back of the grid, have made vast improvements in season 2021. With new regulations coming in next year, the Williams could find themselves as joining the grid as a midfield team, rather than a perennial back marker.

Russell's current teammate, Nicholas Latifi, is expected to remain at the team in 2022, but his new partner is yet to be confirmed. Former Red Bull and Alpha Tauri driver Alex Albon is the front runner after spending a year without a seat, though the 25-year-old's existing ties with Red Bull may make the move difficult.

Toto Wolff, Mercedes team principle, has been open in saying he doesn't want a Red Bull aligned driver in a Williams car that has a Mercedes power unit, given the rising rivalry between the teams.

"It's tricky to have a 100% Red Bull driver on a Mercedes power unit, so I'm happy to work with him as long as they let him free from his Red Bull contract," Wolff said at the Dutch Grand Prix.

Should Albon's path to Williams be blocked, he could find himself partnering Bottas at Alfa Romeo. Current Alfa driver, Antonio Giovinazzi, is facing speculation he could be moved into a reserve driver role, making way for a new line up in 2022.

Williams and Alfa Romeo have also reportedly been considering Dutch driver Nyck de Vries to make his F1 debut. The Mercedes backed driver has built an impressive resume in his career so far, winning the F2 championship in 2019 and the recent Formula E title. The 26-year-old is a current test and reserve driver for Mercedes.

After Bottas' announcement on Monday, Mercedes are set to announce the signature of Russell next, leaving room for Williams and Alfa Romeo to make their decision. Just three weeks after the conclusion of the summer break, the 2022 grid could potentially be finalised before lights out at Monza on Sunday.