Mercedes F1 team boss Toto Wolff says the German manufacturer is happy so far with the way junior driver Pascal Wehrlein has performed in the first four races of his debut season.

The 2015 DTM champion has been given his chance at the pinnacle of the sport this year with Manor, finishing every grand prix, and peaking with a 13th place finish in Bahrain, and while Wolff admits it is still early days, he adds that the early indications are promising.

"He has shown some very strong performances in qualifying and the race, and that is what we were hoping for," Wolff said after the Russian Grand Prix.

"But you can see today he was quicker than [Rio] Haryanto [his team-mate] but not by a lot so he is getting a good fight for his money, and that is good.

"Pascal has completely different responsibilities in Manor than he had at Mercedes and we like that. We see his development in the team, in his rookie year to be lead driver is a tough thing but so far we are happy.

"It is still early to assess [though], he is still very green."

Meanwhile, Wehrlein was disappointed with the race in Sochi, but is hoping for better when F1 heads to Spain next weekend.

"It was a disappointing result [in Sochi]," Wehrelin confirmed. "I got a good start and managed to avoid all the problems in the first couple of corners, then the first stint was quite good for me. I had a good fight with the Saubers but after the first pit stop they were in front of me.

"I tried to push hard to overtake one of them again but I couldn't manage it and I destroyed my tyres behind them so I had to box again.

"At the second stop we had a problem with the left-rear which lost us a lot of time but by then I think 18th was the best we could hope for.

"Now we have to focus on heading to Europe and what we can do to improve. My thanks to the team so far for a good first few races and their hard work."