Lewis Hamilton's race engineer Peter Bonnington will not join the seven-time world champion at Ferrari next year, having committed his future to Mercedes.
Bonnington, known to most race fans as "Bono" from Hamilton's radio messages, has worked with the Brit since he joined Mercedes in 2013.
The role of race engineer is one of the most important in F1 and Hamilton has won six of his seven world titles working with Bonnington.
Hamilton is moving to Ferrari next year and there had been speculation the likes of Bonnington would make the move with him.
Ferrari has already signed Mercedes pair Jérôme d'Ambrosio as its deputy principal and Loic Sera as head of chassis performance engineering.
But Bonnington has pledged his future to Mercedes having secured a promotion to head of race engineering.
Bonnington's promotion will take effect from this weekend's Dutch Grand Prix, although he will continue to work with Hamilton until the end of the season.
Mercedes is still yet to confirm Hamilton's replacement for 2025 although it appears set on elevating its academy wonderkid Andrea Kimi Antonelli from F2.