Nadal has avoided surgery so far, getting therapeutic treatment in hopes of speeding the healing. But the slow recovery from the inflamed knee means Nadal has been trying to lower expectations.
Andy Roddick defeated Nicolas Massu 6-2, 4-6, 6-3, 6-4 on Friday to give the United States a 1-0 lead against Chile in the first round of the Davis Cup series.
The United States doesn't have home-court advantage against Chile but it's favoured even on Santiago's clay courts this weekend.
Nicolas Massu reached his hometown final for the second straight year when he dispatched Spain's Albert Montanes 6-1, 6-3 at the Movistar Open on Saturday.
Top-seeded Nicolas Massu beat Nicolas Mahut of France 6-3, 7-6 (3) to reach the semifinals of the Grand Prix Hassan II on Friday.