Christian Horner on Tuesday said there is "no risk" Red Bull is set to lose Daniel Ricciardo to Ferrari.
Ricciardo, whose frustration with the situation at Red Bull is beginning to show, earlier told reporters that Ferrari’s apparent interest for 2016 is "nice" and "a compliment".
But he also acknowledged that he is under firm contract.
"I don’t have experience with contracts," said the Australian, "but I would never rule anything out completely."
Dr Helmut Marko, however, has said Ricciardo’s deal is "bulletproof", and team boss Horner also says the 25-year-old is definitely staying put.
"There is no risk or discussion of him being anywhere else other than Red Bull for a minimum of three years," said the Briton.
But Ricciardo said he no longer believes Red Bull can catch up with the frontrunners in 2015, even though he thinks that with a better engine, the RB11 would be "in the ballpark" with Mercedes and Ferrari.
He is less convinced that Renault’s hopes of improving its struggling engine can bear fruit this year.
So while Red Bull has car improvements ready to run at Silverstone, Ricciardo said: "In terms of the power, we may find small things over the year, but I think it is what it is for this season.
"But for the car, we have a little bit coming for Silverstone which seems like a promising update. I think Silverstone will be better," he added.