London: Juan Martin del Potro has acknowledged he needs to improve certain aspects of his game if he is to continue his climb up the rankings chart next season.

Coming in as the sixth seed at the year-ending Barclays ATP World Tour Tennis Finals at London's O2 Arena, del Potro went the distance only to go down 6-3, 6-4 to Russia's Nikolay Davydenko at the final hurdle on Sunday.

"Well, I have to keep working. I have many things to improve, like my serve and my forehand. My goal is I'm gonna feel better with this part of the game so I can be in a better position for next season," the Argentinean said.

Compliments for rivals

"But I have some very good players fighting with me, such as Murray, Federer, Djokovic and Nadal. So I know the way to get there is through work," he said.

The lanky Argentinean started off the tournament on the wrong foot when he went down in three sets to Murray on the opening day before making amends with wins against Fernando Verdasco and Federer to qualify for the semifinals ahead of home favourite Murray. In the semifinals, he won a hard-fought three-set verdict against Sweden's Robin Soderling to set a final showdown with Davydenko.

"Maybe I have to improve a little bit in the little things. But he [Davydenko] played much better than me. He played some unbelievable tennis and he beat me in a good way and that's the reason he won," he said.

Del Potro is, however, nearly assured of going into next season as the World No 4 when the rankings are announced.

Sunday's title match was the fourth meeting between del Potro and Davydenko, with the Russian now holding a 3-1 edge over his Argentine opponent.

"He's very strong. I never beat him in hard court or indoors. He's very fast. He plays like PlayStation, runs everywhere and it's very difficult to make winners against him," del Potro said.