Toro Rosso chief Franz Tost does not believe the Faenza based team will lose Carlos Sainz.
Spaniard Sainz has already denied persistent rumours that he could be the subject of a swap deal involving engine price between team owner Red Bull and Renault.
Tost is quoted by Italy’s Tuttosport: "Carlos has a contract and I do not think Red Bull is planning to let him go, especially considering his development."
He added that Sainz, 22, is now "a professional of the highest level, and in 2017 we need a driver like him.
"Considering all the (rule) changes we will have, it will be essential to have an experienced driver, and ideally two," Tost added.
Sainz’s current Toro Rosso teammate is Russian Daniil Kvyat.