Alain Prost believes Renault has transformed itself into a true team thanks to a solid driver line-up made up of Nico Hülkenberg and Carlos Sainz.
The French outfit recruited Sainz at the end of last year in order to improve its overall consistency on the driver front following Jolyon Palmer's disappointing performance.
"Nico is solid, and along with Carlos, they will pull the team upward," Prost told Auto Plus.
"I really believe in Carlos, we'll see how he eveolves.
"What he did in Austin at the US Grand Prix [where Sainz finished 7th] was a good example. He went from Toro Rosso to a big manufacturer's team, where there's always a bit more pressure.
"What he achieved during that weekend was quite remarkable."
"In Mexico, he made a small mistake, which is something we must accept. That's why I wanted him to join us as early as possible, so he could put a few races behind him before 2018. He'll reach more milestones."
For all of Prost's enthusiasm for Sainz, the F1 legend won't know until later this year if the Spaniard will remain with Renault in 2019 as he is on loan from Red Bull for one season only.
"We'll see what's going to happen next year with the market, as it's very open. We need to concentrate on the work with Carlos and Nico."
"Obviously we don't know if we are going to keep him at the end of 2018," Prost conceded. "But we had to make this choice.
"We are not in the position to be world champions yet. So we have to put step by step," he explained.
"We'll see what's going to happen next year with the market, as it's very open. We need to concentrate on the work with Carlos and Nico."
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