Rafael Nadal has said that he is not expecting too much on his return to hard courts at Indian Wells this week.
The Spaniard made his return from injury on the clay courts of Vina del Mar, Chile last month, before going on to win titles in Sao Paulo and Acapulco.
However, he is unsure how his knee will react to the harder surface, stating that he is "not confident" of victory in California.
"The results on clay were positive, especially because the knee was feeling better and better every week, especially last week," Nadal told reporters.
"Now I'm going to try here on hard [court]. I don't know [what might happen]. I cannot say much.
"I'm not confident about what I will be able to do here after one year of not playing on hard. I will try my best. I don't expect anything in results here."
The 26-year-old slipped to number five in the world rankings during his absence.