Felipe Massa says he is baffled by his lack of pace in recent races - and says he cannot understand why he is struggling so much to get comfortable with the 2010 tyres.
The Brazilian has seen team-mate Fernando Alonso seize the upper hand at Ferrari in the last few grands prix, despite the pair having been evenly matched all winter.
Massa thinks the state of affairs is the result of him not being able to work the harder compound tyres that have been used since the season-opening Bahrain Grand Prix.
"Definitely I am not happy because the whole winter in tests I was 110 per cent happy with the car and the way I drove," said Massa after the Spanish Grand Prix, where he was beaten by Alonso all weekend.
"Starting the first race I was 120 per cent happy with the car, and we did a great job in qualifying and the race. After, when we changed these tyres, we did all four races [since] with the same tyres, which is one harder than the tyres from Bahrain, I was struggling.
"I couldn't use the tyres as I want, especially when they are new. So it is something I need to understand. It is not that you finish a lap and you do what you did and were slow. I am outside what I have to be and we need to understand what the problem is."
Ferrari has vowed to do all it can to help Massa rediscover his missing form - as it insists it is not worried the Brazilian could see his performances slump if he loses confidence.
"What we have to do on our side is to make sure that the car is one that he feels comfortable driving," said team principal Stefano Domenicali. "I would say for the first time this weekend that was not really the case, because he started to complain about the level of grip of the car from the beginning, which never happened before. And for Fernando this was the first weekend when he was not so happy about it since the beginning.
"This week is very important to go back and see what has to be done around maybe Felipe's car, maybe in set-up, preparation and downforce level because if we give him a good car he is very good and strong. I am sure about that. It is up to us to give him the maximum we can."