Lewis Hamilton is currently faster than his new teammate Valtteri Bottas, according to Mercedes team chairman and Formula 1 legend Niki Lauda.
Finn Bottas was signed by Mercedes on a one-year contract for 2017, after world champion Nico Rosberg's shock decision to quit the sport.
"What I've seen so far is that Valtteri has closed to within two tenths of Lewis's qualifying performance," Lauda told RTL at the Barcelona test.
"This is already very good. He lacks the experience that Lewis has so he can develop still further on the long runs.
"He has to work on everything, and he will. But I am more than satisfied with his performance so far."
Bottas agrees that he is "close" to Hamilton.
"We have worked on different programmes but sometimes I had the opportunity to compare the telemetry," said the Finn.
"So far it looks like we are very close, but it's only testing. However, based on what I saw, I have made progress."
The 2017 world championship begins with the Australian Grand Prix on March 26.