Jenson Button beginning to understand his new McLaren

Jenson Button feared McLaren would struggle in Melbourne (PA)

Martin Whitmarsh, the McLaren team principal, is hoping the "uncompromising design" of this year's car will not produce more headaches following a tough pre-season.

Whitmarsh has been bandying around words like "challenging", "potential" and "nerves" when speaking about McLaren's pre-season in which Jenson Button and new team-mate Sergio Perez have endured up-and-down days during testing.

The British driver admitted he will not be surprised if they are off the pace in Melbourne in nine days' time. It was not until last Friday that Button enjoyed his best testing day and with it the belief that he is finally beginning to understand the car.

"We've faced a challenging few weeks prepping our new car for the 2013 season," said Whitmarsh. "It's important to remember it is a new and uncompromising design we intend to develop aggressively throughout the year. Undoubtedly, it has great potential, and we fly to Melbourne determined to show well and to score points that should establish us in good stead for the drivers' and constructors' world championships. We're still working tirelessly to bring more pace to the car's performance envelope."

Meanwhile The FIA has confirmed there will be 19 grands prix on this year's Formula One calendar.

A provisional date set aside for an additional European race on 21 July will not be filled after F1 supremo Bernie Ecclestone failed to lure Turkey back on to the calendar.