Martin Whitmarsh and Sam Michael admit McLaren's lack of pace is a worry

Martin Whitmarsh and Sam Michael have both admitted that McLaren are lacking pace as they struggle to understand how to get the best performance from their new car.

Speaking in the Team Principals' Press Conference after practice, Whitmarsh described it as one of his most difficult days in F1. "I would say this is one of the hardest days I can recall and we don't have time to summarise it all now," he said. "I would say we lacking in overall grip and consistency, we had understeer, poor ride and it was a very difficult day. It was a day when we didn't move forward during the course of the day and that is a bit of a concern but we have a lot of data to work through long and hard tonight. "We should have a base we can improve on and hopefully we can do that tomorrow but it was a disappointing and tough day for the team. "It is obviously better to start a season competitive, but we are a strong team and we will find a way through." McLaren topped the timesheets on two of the 12 days of pre-season testing, but speaking ahead of practice, Jenson Button felt that masked some of their performance problems. "The first two tests weren't great really because we had so much to test. We had so much mileage to put on parts we couldn't do any set-up work," he said. "The last test was much better but we haven't run the car the same for two days in terms of set-up. It's not been perfect but on the last day of testing I got a much better feel for the car. "I found something with the set-up and got a direction with the car I liked. But if you look at the testing times, there were certain times that we definitely could not have done in testing in Barcelona."