Bottas fears poor car performance is masking his progress

Where fellow newcomers like Jules Bianchi have impressed in part because of lower expectations, Bottas's maiden season comes amid Williams proving vastly less competitive than it was in 2012.

The team has failed to score a single point in the first six races of this year's campaign, in contrast to a 44-point haul - which put it on the tail of Mercedes - over the same period last season.

Bottas admits such a slump has made his first six races appear underwhelming at first glance, but says that has not made him worry for his future.

"No one expected that we wouldn't have any points until now because everyone was hoping we would make as step from last year," he said.

"The things I'm doing in the car, maybe some good things are very difficult to see from outside.

"That's how it is now. All I can do is just do my best all the time.

"I have got positive feedback from the team and I'm still learning all the time and pace wise I've been matching Pastor [Maldonado], we've been very close."

Asked whether he was concerned about being retained next year, Bottas said: "It's too early to think about that. I just keep focused on the current race and then the next one and the next one.

"I'm more or less [happy with what he has done]. There are always things when you look back that you could have done better and you wish you had done better.

"It's not the easiest first season, the car is quite tricky and we are trying to improve, so it's definitely a big challenge for me - but I like challenges.

"For a rookie year, it has been a good start there is more to come."