Del Potro is Argentina's top player for first time as he enters Davis Cup

BUENOS AIRES, Argentina -- Juan Martin Del Potro will be playing in Argentina as the country's top-ranked player for the first time this weekend when he and his teammates face Spain in the Davis Cup final.

Despite a long season on tour that culminated with a trip to Shanghai for the Masters Cup, the 20-year-old Del Potro said his climb through the rankings to No. 9 has left him confident.

"I already feel better," Del Potro said ahead of Friday's opening singles matches. "There are still three days left until Friday and I think I have enough time to adapt as well as I can."

Del Potro is expected to play two singles matches in the best-of-5 series. He began training with the team Monday, after returning Saturday from China.

"I'll have to make the last push of the year," Del Potro said.

David Nalbandian, ranked 11th, had been the top Argentine player for three years. Nalbandian is 16-4 in Davis Cup singles, and should also play Friday and in Sunday's reverse singles.

Del Potro began the season ranked 50th, but four straight victories heading into the U.S. Open pushed him well up the rankings. His 23-match winning streak was snapped by eventual finalist Andy Murray in the U.S. Open quarterfinals.

"Now I have to put all my effort into the Davis," Del Potro said. "It's the most important objective for Argentine tennis in the last few years."

Argentina has twice reached the Davis Cup final, but lost both times, in 1981 and 2006.

"The season was good, but I hope to finish it winning the Davis," Del Potro added.