A new country and a new start -- Rafael Nadal will cautiously embark on his long-awaited comeback tournament in Chile this week.

The tennis star has not played a competitive match since losing in the second round at Wimbledon last June due to knee problems, and he is wary of pushing himself too hard in his first appearance at the Vina del Mar Open.

"I have to take it slowly and be humble to know that things won't be as good as they were before my injury. I need to be patient," the 11-time grand slam champion told reporters.

"I need weeks of working on the circuit. This is my first week and I don't think the goals are the same that the ones I will have in two more months."

Nadal is hoping to defend his French Open title yet again, aiming for an unprecedented eighth crown in Paris, but the Spaniard's 2013 preparations were ruined by a preseason illness that forced him to miss last month's Australian Open.

He decided the skip the hard-court event and go straight to his favored clay surface, on which he will also play in a Brazilian tournament after Chile.

"I hope the tournament will help me to get the feeling I need to add week after week after a long period without competition ... results are the least important thing right now," said Nadal, who last week launched a smartphone app that teaches tennis skills.

"If my knee doesn't hurt I have no fear. I've had had more serious injuries in the past and I got stronger after them," he added.

"This is the injury that has sidelined me the longest so maybe it will take me a bit longer to get back my confidence, the good feeling on court, but if my knee doesn't hurt I don't see why I couldn't get back my movements and game style."

The 26-year-old will take to the court on Tuesday for a doubles match, then start his singles campaign the following day after receiving a first-round bye as the top seed in the draw despite slipping to fifth in the world rankings.