Players defend Rafael Nadal

SHANGHAI, Nov. 9 (UPI) -- Several players defended the decision of World No. 1 Rafael Nadal not to play in the men's season-ending Masters Cup tennis tournament.

The Spaniard announced last week that he would not compete at the event in Shanghai, citing fatigue tendinitis in his right knee.

The event started Sunday.

"The organizers are not happy," Serbia's Novak Djokovic, the third seed, noted, but said Nadal's decision was "totally understandable."

"Rafa has earned every right to pick and choose what he wants to prioritize," agreed American Andy Roddick. "He's also responsible to his teammates and his country."

Spain is to play Argentina in the Davis Cup final starting Nov. 16, but Nadal has not said anything about his playing status for that matchup.