The Faenza-based team suffered this season from the lack of development of its 2015 Ferrari engine, which remained in the same specification throughout.

Toro Rosso finished seventh in the standings, and will be back with Renault power units in 2017.

"Renault look very competitive on the engine side," Sainz told Motorsport.com.

"So I'm positive and thinking that if James [Key] and his team can keep doing the same job with a decent engine, this team can take a step forward next year.

"Toro Rosso has shown in the last few years that the chassis is good enough for P5 in the championship, and that is our target.

"We just didn't have the full package for that. But Toro Rosso and James are capable of doing that, at least on the chassis side.

"We are a great family, an Italian or Latin family with some good English people at the top helping us. I am convinced this team is capable of more things next year, when everything clicks."

Sainz says the team did better than expected in the latter part of this season, despite the lack of engine development relative to its main rivals, which proved particularly costly at high speed venues like Monza and Spa.

The Spaniard finished 12th in the championship.

"I think it's been incredibly positive this year, particularly after Barcelona, when things clicked and we started having very strong results.

"And even in the second half of the season we still managed two sixth places, 16 points. Probably my two highlights of the year were Austin and Brazil.

"I'm extremely proud of the team to still keep pushing in the second half with motivation levels for sure quite low."