Formerly Ferrari's chief of vehicle concept, Sanchez was initially hired by McLaren in March 2023, and finally re-joined his former team in January after completing his gardening leave period.
Sanchez was going to be one of three technical directors to succeed James Key, being responsible for car concept and performance, with Rob Marshall brought in from Red Bull to head up engineering and design, and long-time McLaren aerodynamicist Peter Prodromou the TD for aerodynamics.
But last week it was announced Sanchez and McLaren had already parted ways after just three months in the job.
Instead, McLaren announced changes to its technical structure, with Stella taking over from Sanchez in a streamlined performance role in the interim until a replacement has been found.
There has also been a swap between Neil Houldey and Marshall, with Marshall now chief designer and Houldey the technical director of engineering, a role which he was originally set to hold before McLaren landed Marshall. Prodromou, meanwhile, remains in post as the aero tech director.
Motorsport.com understands that once McLaren's long-awaited line-up was fully in place this winter, Sanchez realised his remit in Woking wasn't what he had envisaged when he signed up over one year ago.
It was this unease with his level of seniority that led to talks between him and Stella and ultimately what Stella called an "amicable" conclusion to part ways. Sanchez's departure then triggered a further reshuffle.
"We all agreed that the model itself is very valid, we are very happy to have three directions: aerodynamics, engineering and performance, this works very well," Stella explained.
"But when you need to find the technical configuration, you also need to make sure that it plays to the strengths of the players.
"We had conversations with David about this topic and we realised and acknowledged that his level of seniority, expertise, competence is potentially even more senior than the role that he was having at McLaren."
McLaren agreed to release Sanchez early so he could pursue opportunities elsewhere. It is therefore understood that any gardening leave is set to be kept limited to help land him a suitable new role.
Explaining the call to release Sanchez so quickly rather than waiting to see how the situation develops, Stella said: "Three months in normal industries is not a long time, but in Formula 1 it is a long time.
"Wating another three months can put you off-phase with some of the work for next year's car or the work you need to do already on the 2026 car.
"And this is valid for David as well, to give him fair chances somewhere else to have bigger roles, three months can make the difference.
"So, we thought that was the right time and we came to an amicable, friendly conclusion that it was the right thing to do. And I really wish him all the best for his future endeavours."
Stella stressed that McLaren's technical organisation is under constant review as it integrates new hires, which go well beyond the headline Marshall and Sanchez signings.
The Italian felt Woking was now in a stronger position after its latest round of changes.
"The news about David is part of the news. The main news that is relevant for McLaren is that we have an updated, evolved technical configuration, which I think puts McLaren in an even stronger position than we were before," he added.
"The new recruits don't only include some senior people, but actually we have added many people in the technical area at McLaren, what we call internally the additional horsepower.
"What we have done in these first three months was to find the right synthesis between the technical journey that we started last year and this additional horsepower."
