Red Bull: Christian Horner warns rivals over Ricciardo & Verstappen

Red Bull have warned rival teams interested in their drivers that they are not available.

Red Bull's Daniel Ricciardo and Toro Rosso's Max Verstappen are interesting Ferrari for 2017 as potential replacements for Kimi Raikkonen.

But Red Bull team principal Christian Horner said: "I'm not going to go into details of their contractual status.

"But rival teams are speaking to the wrong people if they're talking to the driver as the driver has a contract."

Ricciardo last winter signed a new four-year contract with Red Bull, which takes him to the end of 2018.

Verstappen, who has impressed since making his debut for junior team Toro Rosso this season at the age of 17, is under contract to Red Bull until the end of 2017.

Sources close to Ferrari say the team are already considering which drivers could replace Raikkonen at the end of next season.

Ricciardo is their number one choice, but they are concerned signing him would be disruptive to number one driver Sebastian Vettel, whom the Australian beat when they were team-mates at Red Bull in 2014.

For that reason, they may be more likely to go after Verstappen.

However, it is not a foregone conclusion that Ferrari will drop Raikkonen at the end of next season.

Earlier this year they had doubts about continuing with him for 2016, but decided to keep him after all.

Verstappen said of his future: "I'm never in a hurry but, of course, if you have two fourth places you're very close to the podium, and you want to be on it.

"But I still have a lot of things to learn and I'm pretty happy where I am right now - but hopefully in a couple of years I can fight for victories.

"I think everybody wants that."

Full Brazilian GP practice results

Brazilian GP coverage details