Sergio Perez has said he was pleased with his pace during the 2011 F1 season, although the Mexican admits that his heavy accident in qualifying for the Monaco Grand Prix had a much bigger impact that the two races he was forced to miss.

In his first year in the sport with Sauber, Perez scored 14 points and was the second rookie in the standings behind Force India's Paul di Resta.

However, the accident in Monaco - where he crashed heavily in Q3 - proved to have a major impact on Perez's campaign as he also missed the following race in Canada and didn't feel fully fit until the Hungarian Grand Prix.

"I'm happy in terms of the speed I had but I'm not happy in terms of results and points," he said when asked about his maiden season. "Also because of my accident I missed two races - Monaco and Canada - in which the car and the team performed very well. After I got back into the car it still took me a few more races until I was really a hundred percent again.

"Physically I had to wait. This wasn't easy, but it was important. When I got back into the car for free practice in Canada I realised the difficulties I had. I felt dizzy, so it was impossible to drive. Two weeks later in Valencia I felt a lot better and was able to drive. It was better again in Silverstone and at the N?rburgring, but it was only in Budapest that I felt I was completely over it. It had been a very heavy impact and I learnt it takes time to physically make sure you feel right after suffering from concussion. Mentally it was a shock too. It helped me a lot to go home to Mexico and it was important to do all that work to prepare for racing again.

"But regarding my overall performance in F1, I think I can be happy with my rookie season."

Perez admitted that moving up from GP2 had been a huge step, with the amount of pressure he faced being 'on another level'.

"Formula One is a completely different world," he said. "When you arrive there everything is new. The amount of people you work with, the level of the work and the amount of work. Every detail is important outside and inside the car. The media interest is huge and all together this also has an impact on your private life. It is impossible to pick just one single aspect. You have to consider it all as one.

"I have had a lot of pressure during the whole of my career, but in Formula One you step up to another level. In the winter everyone was saying I was a pay driver and it was good to prove them wrong. There were a lot of ups and downs during the season and the team's support always helped me to remain confident."