Andre Lotterer has warned against expecting too much as he tackles his first Formula 1 grands prix with Marussia.
The 32-year-old will take to the grid this weekend in Belgium after being called up to help the team's development of the CT05.
Lotterer, who is replacing Kamui Kobayashi at the backmarker team, is a three-time Le Mans winner and has a great deal of experience in other series.
And although he is hoping to put that to good use this weekend, he admits it won't be easy.
"I will have to learn everything very fast so don't expect too much from me!" the German driver said.
"In F1 it's a lot that is dictated by the car and I'm aware that unfortunately - I don't want to speak bad about the team - we don't have a winning car but we have an updated package and I hope that I can bring all my experience and speed as fast as possible.
"It's an unusual situation so the wins in other categories gave me the confidence as well to think 'OK I have an established career on the other side' - which is Le Mans with Audi and also in Japan - so I don't have much to lose by doing this, let's say."
He added: "Caterham asked me to race here. It's not just for fun or for my personal interest, it's to give my best and to help them.
"We will try to do a weekend without mistakes initially and if I have the opportunity to so something good, I do it."