Current Red Bull driver Sergio Perez is contracted to race for the team next season, but his position has come under threat following a series of poor performances.
Team principal Christian Horner has refused to guarantee that the Mexican will still drive for Red Bull next season despite his contract status.
On Friday, Gazzetta dello Sport claimed that, while Red Bull had not come to a final decision, RB's Liam Lawson would be their candidate to replace Perez for 2025 if that eventuality were to occur.
But now, a shock driver has entered the frame for the seat that no-one has considered.
Last Word on Sports are reporting that Red Bull are in advanced talks with Williams over signing Franco Colapinto for 2025.
While it was expected that, if Colapinto signed, he would be given the second seat at RB with Lawson getting the promotion, it is now claimed that the Argentine is Red Bull's 'priority' option for the works seat.
Such a move would send shockwaves through F1, with the 21-year-old only having had eight Grands Prix of experience before the 2025 season gets underway.
But he has made a positive impression since replacing Logan Sargeant at Williams following the Dutch Grand Prix, and has regularly competed with or even finished ahead of his far more experienced team-mate Alex Albon.
Red Bull advisor Helmut Marko stated last month that the team had approached Colapinto's representative, while Horner spoke about his talents during the Brazilian Grand Prix weekend.
Horner told Sky Sports F1: "It's great to see the juniors doing a great job.
"I think Franco, again, is a kid that's doing really, really well. Of course, you're always keeping an eye on the driver market and I think Franco is a potential star of the future."
If Colapinto were promoted to the Red Bull works team, it would potentially provide some questions for the team to answer given that Lawson and Yuki Tsunoda are both in their driver academy and would have been overlooked.
Perez is only one of three non-Red Bull academy drivers signed by the team, with David Coulthard and Mark Webber driving for them between 2005 and 2008 as well as 2007 to 2013 respectively
