Spain's Rafael Nadal, who is making a comeback from a serious knee injury, teamed up with Argentina's Juan Mónaco to beat the Czech duo of Frantisek Cermak and Lukas Dlouhy 6-3, 6-2 in doubles at the ATP event in Viña del Mar, Chile.

"The knee is there, the doctors say it is fine, there is no fear of breaking down, but the knee keeps hurting," Nadal, who was out of action for seven months, told reporters.

Nadal began last summer on a high note by capturing a record 7th French Open title with a victory over world No. 1 Novak Djokovic of Serbia in the final, but he pulled out of several events after a shocking second-round loss at Wimbledon.

"If it hurts, it hurts and I endure it, but there may be days when I cannot compete at 100 percent," Nadal said.

The tennis star, who has won 11 Grand Slam titles, said after the doubles match that he was playing "with pain."

After the match, Nadal was named a "Distinguished Son of the City of Viña del Mar" by Mayor Virginia Reginato.

Nadal told Efe in August that he was suffering from a knee ailment known as Hoffa's syndrome, which is also known as fat pad impingement and causes pain and swelling around the bottom and under the kneecap.

The Spaniard, known for his physically demanding style of play and incredible defensive skills, has struggled to stay healthy during his career, having been forced to withdraw from each of the four Grand Slam events due to various injuries. EFE