Ferrari’s Kimi Raikkonen further sealed his team’s position as early-season favourites with the fastest time of the winter in pre-season testing at Barcelona on Friday.

And while Hamilton says there are no alarm bells ringing about Mercedes’ progress during a mixed week of final testing, he suggest that he had not yet got the best out of the car.

“I haven’t got it into a good window yet,” he said, when asked by Motorsport.com about whether or not he felt the Mercedes was as fast as his main opposition.

“I don’t know if it can go as fast as them. I really don’t. We will find out. We hope we can. They have done a fantastic job, as I said.”

He added: “Do we have more potential? Time will tell. Again, we have just been focusing on trying to understand this car and get the most of out of it.

"We’ve had up and down days and there has generally never been a perfect day but there is a lot of potential in the car to continue to grow but I will say the others look very, very fast.”

Three way fight

While Mercedes still has two weeks to work out its final package for the Australian Grand Prix, Hamilton suggests that things are close at the front – with a proper three-way fight for victory.

He also distanced himself from his comments on Thursday that Ferrari had been ‘bluffing’ by not showing its full potential.

“I don’t know where the bluffing came from? Did I say that? Maybe I did... I didn’t realise I was saying it,” he said.

“I think they have been doing a fantastic job and there is more to come from them. I think their pace here this week has really been spectacular and still Red Bull are there.

"I don’t know if they’ve brought their upgrade package here this week, but usually they bring it to the first race so I expect us to have a serious battle with both these teams.”

No more pace

Raikkonen’s best lap of 1m18.634s set on Friday was seven tenths of a second faster than Hamilton’s best time of the winter – 1m19.352s.

When asked if he felt he could have produced a lap in the 1m18s region, Hamilton said: “Driving today, the time you saw was the time I could do. So, I didn’t feel when I got out that I could have gone faster.

“But of course there are all sorts of things that could come into play to bring the time down, such as fuel loads and engine modes.

“So the great thing is that nobody really knows. It looks very positive for Ferrari that is for sure, and I don’t think that is a bluff. I think that is real speed. They have done a great job.”