Michael Schumacher is concerned about the amount of ground Mercedes has to cover in order to be competitive at the start of the season.

Schumacher has had a positive couple of days at the wheel of the W02 at Jerez, with no sign of the hydraulics problems that set the team back at the first test at Valencia. He set the fastest time of the week on Friday and followed it up with the third fastest time on Saturday. However, he said there is a huge gap between where Mercedes is now and where it needs to be in order to run at the front at the start of the season.

"Compared to past experience, between the first test and the first race there was a margin of ... whatever," he told BBC Sport. "If you look at it now, it looks like it is five or six times more - this margin that you develop. It is very difficult for me to judge who is in what development position - we know where we are. Yes, we are slightly concerned but then on the other hand we know where we will and want to go to. The first race will tell us truly what is the situation."

He admitted Mercedes had lost ground at Valencia where it failed to complete its testing programme and that the recent headline times were of little consolation.

"I don't think we managed to do as many miles as we wanted at the first test," he said. "Lap times, yes they are important but maybe not right now. Naturally if you are quickest all the time that would be the perfect situation but we know coming from last year this is not possible and we have to build up our way."

Schumacher added that getting the car to work in harmony with the Pirelli tyres was one of the biggest tasks for all the teams.

"We have a character of car that we built up, but we have a new character of tyres and how much they will be in harmony is difficult to say at this point in time.

"To have a good harmony seemed less important last year and is more important this year."

Times