Adrian Newey admitted that his future with Red Bull is uncertain after Ferrari made another attempt to recruit the technical wizard.
Newey is regarded by many as the brains behind the four consecutive titles for Red Bull and Sebastian Vettel, having designed championship-winning cars for both McLaren and Williams earlier in his career.
The Red Bull Chief Technical officer previously dismissed approaches from Ferrari, stating a desire to stay in his native England as the reason.
But following a largely uninspiring Spanish Grand Prix, where Fernando Alonso finished sixth and Kimi Raikkonen seventh, it has been more than a year since Ferrari last won a Grand Prix and it is believed that Ferrari is once again eager to land Newey's signature.
During an interview with Sky Sports ahead of Sunday's race in Barcelona, Newey admitted that his future at the Milton Keynes team is far from secure.
"I don't know. I need to think about it. We're in the middle of the season and I'm just getting on with it," he told Sky Sports when asked about his long-term future.
Sky Sports spoke to Newey again after the Sunday's race, and he maintained his vague stance.
"At some point I am going to have to think about the future, but at the moment my focus is getting in front of the silver cars," he said.
Red Bull Team Principal Christian Horner was unable to dismiss the claims that Newey is Ferrari-bound, and said that asking about the length of his contract with Red Bull is like "asking a lady about her age".
Nevertheless, Horner believes Newey remains committed to their cause.
"A lot of approaches are made to our staff, but he enjoys the environment at Red Bull and he has always said he would like to finish his career at Red Bull. The team have a great relationship with Adrian," Horner said.
"For sure, the lure of Ferrari is always there, but there's the politics and the pressure that goes with it and the fact is in Italy. Lots of us have been linked with Red Bull but so far none of us have gone."