Mercedes Formula 1 boss Toto Wolff believes Valtteri Bottas is operating at a higher level than ever before, despite the squad’s decision to cut him loose at season’s end.

This year will be Bottas’ fifth and final at the Anglo-German squad, with George Russell being promoted from Williams next season in his place.

The Finn in turn will head to Alfa Romeo to replace the retiring Kimi Raikkonen.

Bottas has bagged eight podiums from 14 starts in 2021, perhaps none more impressive than his drive from the back row of the grid to third at the most recent race at Monza.

The Italian Grand Prix easily could have been a drought-breaking win for Bottas, having qualified fastest on Friday and gone on to win the Saturday sprint, only to be shuffled back due to a power unit change.

Thus, Sochi – the venue of this weekend’s Russian Grand Prix – remains the last circuit where Bottas stood on the top step of the podium, almost precisely 12 months ago.

The 32-year-old also won there in 2017, and Mercedes in fact has never been beaten since Sochi’s 2014 debut.

Wolff heaped praise on Bottas’ form as part of his preview column for the 2021 Russian Grand Prix.

“Lewis is in the 10th championship battle of his F1 career, and he is laser focused on what he needs to deliver in the next eight races,” he wrote.

“As for Valtteri, he’s driving better than ever, like we saw in Monza – and he will be flat out every weekend.

“There’s a calm determination about the team right now and the business end of a season, fighting for championships, is exactly what we enjoy the most.”

Max Verstappen leads Lewis Hamilton in the drivers’ championship by five points – but will take a three-place grid penalty into Sochi – while Mercedes is 18 points ahead of Red Bull in the constructors’ standings.