Red Bull boss Helmut Marko has cast further doubt over Nyck de Vries' future with AlphaTauri after admitting Christian Horner was right to have reservations about signing him.
De Vries was signed to Red Bull's junior team after an impressive points-scoring finish on his F1 debut at last year's Italian Grand Prix while deputising for Williams' Alex Albon.
The Dutch driver has had an underwhelming start with his new team this year and there were reports last month that Marko, the head of the Red Bull programme and the person believed to have the most sway over driver decisions, had given him an ultimatum to improve in time for the Spanish Grand Prix.
That race has come and gone with De Vries still in the seat but Marko has suggested he is still not convinced the Dutch driver is the right person for the role.
Asked on The Inside Line podcast if he and Red Bull boss Horner often disagree about signings, Marko said: "Not often, but sometimes we do. The last one... I would say de Vries.
"Basically it's AlphaTauri, but we're a big family and we get opinions. He [Horner] was not a fan of De Vries. I would say at the moment it looks like he was right."
Sources have told ESPN that Daniel Ricciardo is open to a return to AlphaTauri, but is not willing to do so until next season. Eight-time race winner Ricciardo is currently taking a year out as Red Bull's third driver.
Last week, F1.com reported that AlphaTauri have said a seat is available for Ricciardo next season if he wants it -- Marko's comments suggest De Vries would be in the firing line.
Although De Vries' teammate Yuki Tsunoda has had a mixed career since joining AlphaTauri in 2021, his form this season has been much improved.