Daniel Ricciardo admits he was impressed by the way Daniil Kvyat turned things around last season, adding "there is room for improvement".
Kvyat was thrown in at the deep end as he was promoted to a Red Bull race seat just one season after making his Formula 1 debut with sister squad Toro Rosso.
And he initially appeared to struggle as Ricciardo outscored him comfortably during the early stages of the campaign while Red Bull's problems with engine partner Renault also didn't help.
However, he grew into the job as the season progressed, claiming a career-best P2 in Hungary
"He [Kvyat] has shown speed, I can't say he is not quick," Ricciardo is quoted as saying by crash.net. "He has some good qualifying and races, so throughout the season he is showing some signs.
"I think what was probably surprising or good from him was the first four or five races, it seemed he wasn't quite up to speed, whether it was with a bigger team or the new car, it looked like he would either learn quick or it would be a disaster of a season for him. He turned it around quickly."
Kvyat ended up two points better off than his team-mate in the standings and Ricciardo believes there is more to come from the Russian.
"He has maintained a pretty good level of performances. We can work who had DNFs [laughs], but he has done well," he said.
"I think he has adapted well, picked himself up when he had to and he is still young so there is room for improvement and growth. I think he is more comfortable with the world of F1."