Former Formula One world champions Mercedes announced the surprise departure of chief technical officer (CTO) Mike Elliott on Tuesday, only months after he took on the role in a job swap with James Allison.
Elliott had been appointed technical director in July 2021, with Allison moving to the CTO role, but they switched positions last April after Mercedes made a slow start to the season following a difficult 2022.
Red Bull have won the last three drivers' titles with Max Verstappen as well as the 2022 and 2023 constructors' championships.
Mercedes are second in the standings with three races remaining and have seven-time world champion Lewis Hamilton chasing the runner-up spot behind Verstappen, with the Briton 20 points adrift of Red Bull's Sergio Perez.
Mercedes said Elliott, who had been with the team for 11 years and through their record eight successive constructors' titles, had chosen to depart after developing a technical strategy for the future.
"Mike has been one of the pillars of the team's achievements over the past decade," said co-owner and principal Toto Wolff in a statement. "And it's with truly mixed feelings that we say goodbye to him today.
"Mike is a fiercely intelligent technical brain and a great team-player; he has made a strong contribution not just to winning racing cars but also to building the culture of our team.
"But on the other side, it's clear that he's ready for new adventures beyond Mercedes, so I know this is the right step for him to take, too."