McLaren have announced a leadership reshuffle after Eric Boullier resigned as racing director.
Boullier recently insisted he is still the right man for the job amid reports of unrest at the Woking-based Formula One team.
The Frenchman, who joined McLaren after leaving Lotus is January 2014, offered to quit on Tuesday and chief executive Zak Brown accepted his resignation.
Chief operating officer Simon Roberts will now oversee production, engineering and logistics, while Andrea Stella takes over as performance director.
Former IndyCar driver Gil de Ferran, who helped coach Fernando Alonso at last year's Indy 500, takes the role of sporting director after being recruited by McLaren as an advisor in May.
Brown said: "The performance of the MCL33 in 2018 has not met the expectations of anyone at McLaren, especially our loyal fans. This is not the fault of the hundreds of committed and hard-working men and women at McLaren.
"The causes are systemic and structural, which require major change from within. With today's announcement, we start to address those issues head on and take the first step on our road to recovery.
"I would like to take this opportunity on behalf of the entire team to thank Eric for his service and contribution to McLaren and wish him well in his future endeavours."
Boullier stated: "I am very proud to have worked with such a brilliant team over the past four years, but I recognise now is the right time for me to step down.
"I want to wish everyone at McLaren the best for the remainder of the season and for the future."
McLaren have amassed just 44 points this season, four of which were earned by Alonso at the Austrian Grand Prix last weekend.
