After being granted a one-year extension to his contract with the team, it seems Mark Webber will struggle to keep his seat at the reigning Constructor's Champion beyond 2013.
The 36-year-old Australian will be with the team for the seventh consecutive year this season, but he has already been put on notice by Red Bull's special advisor Dr. Helmut Marko.
Marko has made it clear that Red Bull was unhappy with Webber's performance at Interlagos, where team-mate Sebastian Vettel was competing with Ferrari's Fernando Alonso for the driver's title.
Flavio Briatore, who is involved with the management of Webber's career, noted after Brazil that "the only one who helped Ferrari was Webber."
"Mark was not optimally co-operative in Brazil," the tough Marko confirmed.
According to German publication Sports Bild, several drivers are being considered for a potential drive at Red Bull, with Toro Rosso's Daniel Ricciardo and Jean-Eric Vergne mentioned, but Marko is particularly keen on Nico Hulkenberg.
Another German, the 25-year-old Hulkenberg recently signed a one-year deal with Sauber and has also been linked with a move to Ferrari in 2014.
"A few years ago he was on the list of candidates for our junior team, but Nico already had a main sponsor (Dekra) with which he didn't want to separate," Marko confirmed.