Juan Martin del Potro is aware that he needs to improve his all-round game if he is to challenge the world's top-four players on a regular basis.
The 21-year-old Argentinian was a surprise winner of the US Open in August when he shocked world number one Roger Federer at Flushing Meadows and he also reached last month's ATP World Tour final.
Although he was beaten in London in straight sets by Nikolay Davydenko, del Potro has been pleased with his form in 2009.
He said: "I have to keep working. I have many things to improve - my serve, my forehand. My goal is to feel better with this part of my game so I can be in a better position.
"But I have very good players fighting with me, like (Andy) Murray, (Novak) Djokovic, Federer, (Rafael) Nadal. So I know the way I need to work.
"If I'm in the final, I want to win but in London all the players are very good. So I had a good tournament anyway."