Toro Rosso team principal Franz Tost has said he is "very optimistic" that Renault will provide an engine that is capable of competing with Ferrari and Mercedes.
Senior team Red Bull have struggled to keep up with the leading duo so far this season, but Tost believes the gap will close to them once the teething issues with the Renault engine have been resolved.
"Renault has built a complete new engine for this season – and the pace is very good," said Tost in a Q and A session on the official Formula 1 website.
"Of course with all new things you might have some teething issues. I am optimistic that Renault will to a large extent already close the gap this season and I am very optimistic for next year
"Now what is needed is time to eliminate any teething problems – and mileage."
Tost also said that he had no issue with Carlos Sainz's actions in the incident with Lance Stroll at the Bahrain Grand Prix.
He added: "If you don’t risk anything you don’t get anywhere, so I support drivers who take risks. I hardly criticise a driver if he risks something and it doesn’t work out."