Even though team owner Red Bull has taken up its option on Toro Rosso driver Carlos Sainz, rumours continue to swirl around the impressive young Spaniard.

Formerly comparable to the teen sensation Max Verstappen at the Faenza team, 21-year-old Sainz was being linked with Renault and even Ferrari prior to Red Bull declaring that he has been contractually retained for 2017.

"We are very happy that Carlos is with us again next year," team boss Franz Tost told El Mundo Deportivo.

"The future looks very good for him because I am convinced that next year with a Renault engine and Red Bull technology, we will have a competitive car."

As for the continuing Renault and Ferrari rumours, one suggestion is that Red Bull decided to take up its 2017 option on Sainz so early so that interested teams would need to pay dearly to buy him out of his contract.

Tost said: "Carlos has a contract with Red Bull. If they extended it early, it is a way to make the team stay focused on the job."

Asked specifically about Renault and Ferrari's rumoured interest, Tost added: "I know nothing about the interest of other teams. Red Bull has exercised the option in order to keep him."

Sainz's friend Fernando Alonso was asked in Austria if he thinks his young countryman is ready for a works team like Renault or Ferrari, and according to AS he answered: "Yes, probably yes. The second part of the question is whether he wants to go to those teams.

"First of all I am happy for him because he will have at least three years in formula one and that's very good in terms of continuity.

"I think Red Bull has made a good decision because he is a great driver. For Ferrari, I think from May to September there are always rumours and every driver seems to be on the list."

The championship continues with the British Grand Prix this weekend.