Mat Coch writes:

Two mistakes in as many days have left Bruno Senna dangling at the wrong end of the grid, after his team opted to change his gearbox following his crash in qualifying.

The Brazilian initially scraped through the opening phase ahead of Kamui Kobayashi before tagging the wall and damaging his car without setting a time in the second part of the session.

"Yesterday I made a small mistake that cost me some experience," the Brazilian explained. "In qualifying another mistake cost me a position on the track. It's a tough game, and this is a track that doesn't forgive mistakes."

Senna denied the pressure to perform was forcing him into mistakes and that his were 'normal' driving errors. "Pressure shows when you're making mistakes into braking areas, going off and just hitting kerbs and flying off the track. This was just not leaving enough margin for any eventualities. Yesterday the same thing happened.

"I was confident that I would have enough margin to get near the wall, but obviously near the wall the grip level is not as high as on the track. The little slide that I got, from what we can see, the amount of damage on the car is small."

However on closer inspection the team found the Brazilian had in fact damaged his gearbox, forcing him to take a five-place grid penalty which will drop him to twenty-second on the grid.

"The good news is the car is competitive," he said. "We've seen yesterday with Pastor's run on high fuel that the tyre degradation is pretty decent for us."

Senna's problems can largely be traced to his inability to master the revised Pirelli rubber this season. Though only small changes were made, when combined with a new car it's seen the 28-year-old struggle to get on terms.

"It's a random event if I can make the front tyres work or not," he said. "Sometimes they work, sometimes they don't work. The lap-time reflects that. In Hungary we had the front tyres working pretty much all the way and that was a great weekend.

"This thing in qualifying goes away in the race. In the race I'm always very strong," he stressed. "Definitely there's a whole world of understanding the tyre that I'm struggling with this year."

However Senna doesn't believe the problems are unique to him. "You can sometimes see a big difference between teammates. That shows similar things happening in teams where in the past teammates where much closer.

"It's a tyre and driving style combined thing, and it's my obligation to try and sort it out."

With teammate Maldonado on the front row of the grid and highly rated Valtteri Bottas waiting in the wings, Senna may not have a whole lot of time left.