The problem was with the left front brake which was down on temperature and kept locking. Once you lose that confidence and rhythm under braking, it's very difficult. It is a potential issue for the race but I'll talk to our guys now and we can have a good look at it. Hopefully we can try and sand down the disc a little and then tomorrow should be better. The vibration that I had was just a minor flat spot so I'm not worried about that. Nico did a great job this afternoon and at the end I couldn't get close to him so I'll have to try and make it up tomorrow in the race.