Dr Helmut Marko has hit back at rumours that Red Bull junior Pierre Gasly is set to take over Daniil Kvyat's Toro Rosso seat with immediate effect.
At Monza on Sunday, French GP2 driver Gasly reportedly told Spanish television Movistar that he looks set to make his debut in Singapore.
"I hope that's true," he said, "but first I would need to see with Helmut Marko. I know that he expects the GP2 title from me, and I'm working on it."
A variation of the rumour is that Russian Kvyat could subsequently be loaned to Renault, in exchange for a better deal for Toro Rosso's 2017 engines.
"I don't care about rumours, I'm just doing my job and whatever will be decided will be decided," Kvyat said after the Italian Grand Prix.
Red Bull driver manager Marko, however, hit back at the rumours.
"It's the first time I hear it," said the Austrian.
"Believe me, I'll call [Gasly] immediately. But I don't believe he's stupid enough to have said that."
Marko said that Kvyat, who was demoted from Red Bull's senior team earlier this year, needs more time to recover before a decision about the future is made.
"All of the problems at the moment are on his car," he said. "It would be unfair to blame him.
"When we have enough information, we will made a decision."
As for the rumours of a deal with Renault involving Kvyat, Marko added: "We have a valid contract with him, and we may at any time use the option. So I don't understand what it's all about."
Gasly, 20, distanced himself from the rumours as well.
"Better to make it clear now," he wrote on Twitter. "(I) never said I would replace Daniil in Singapore, (I) just said I hope to get my opportunity in F1 asap."
The 2016 championship continues in two weeks with the Singapore Grand Prix.
