Esteban Ocon's Mercedes Formula 1 ties were a turn-off for McLaren when it came to deciding who would partner Carlos Sainz Jr in 2019, its CEO Zak Brown has revealed.
Ocon was a strong contender for a seat at McLaren, and even had a seat fitting earlier this year as the team pondered a potential mid-season switch for the youngster.
But those McLaren talks went quiet when Ocon moved closer to a move to Renault instead, only for that option to fall through when the manufacturer took Daniel Ricciardo.
While Mercedes, which looks after Ocon's career, pushed again to get him back in at McLaren, in the end the Woking-based team felt Mercedes' long-term control of him was not what it wanted.
McLaren instead opted to promote its own youngster Lando Norris, who it felt was a better longer-term bet even though he is a rookie. Speaking about the Ocon situation, Brown said: "Ultimately, I think we want to have our own driver, and Lando is who we wanted.
"Esteban is someone that we rate extremely highly, and I think any time when a driver, you're looking to something long-term, has ties to another manufacturer, that's a tick in the wrong box.
"Hopefully Esteban will get a ride, or maybe stay where he is, because he certainly deserves to be in Formula 1.
"But manufacturers having a hold on these drivers is certainly something that is a negative when you are not with that certain manufacturer, and you want to have a five, or 10-year view on whether you can have the driver or not."
Norris has been a McLaren young driver since last year, while Brown has helped guide the Briton's career too - but he denied any conflict of interest in promoting him to the F1 team.
"I've been looking after Lando before I started at McLaren and before he came to McLaren," added Brown.
"It's been very transparent from day one with the shareholders, and what we do, and I think I'm not the first person to have that type of relationship in the sport or in business.
"I'm not conflicted in any sort of negotiation so it's quite relaxed around here. He's here on his merit and if he wasn't here he'd be in another Formula 1 team."