VINA DEL MAR, Chile -- Rafael Nadal says he's not focused on winning his first match in eight months when he returns next week at the Chile Open.

Nadal said Saturday that results aren't as important for now as reaching "an acceptable level," after a left knee injury forced him to take the longest break of his career.

"After spending more than six months without competing, I'm not thinking about become No. 1," Nadal said at a news conference. "It's something that even when I'm in good shape and starting the year, I don't plan, so I'm not going to plan it now. My objective now is to go week by week and do the best I can in every game I play."

The 11-time Grand Slam champion says his knee has improved but it still hurts sometimes and he's going to remain "humble and patient" in his comeback in the coastal resort city of Vina del Mar.

Nadal began downplaying his performance in Latin America before he even set foot in Chile.

The clay tournament in Vina del Mar is expected to be safe ground in preparation for the French Open, the only one of the four Grand Slams that takes place on clay and which Nadal has won seven times -- more than anyone in history.

Nadal hasn't played since losing in the second round to Czech Lukas Rosol at Wimbledon in June.

The 26-year-old Spaniard said he'd passed six blood and urine doping tests since then. In the wake of cyclist Lance Armstrong's doping admission, Nadal said he supports strict controls to keep tennis clean.

"Above all, the sport must be clean. We must have certainty that the rival in front is as clean as I am," he said. "I don't have any problem with having controls every week to combat what has happened in other sports. Tennis continues to be a clean sport as it has been throughout its history."