Melbourne - Luckless Grand Slam winner Juan Martin del Potro on Sunday pulled out of the Australian Open after a recurrence of his troublesome wrist injury, but remains confident of resurrecting his career.
The giant Argentine spent almost a year on the sidelines before making his return as a wildcard at the Sydney International last week, where he made the quarter-finals.
But he said he was not ready for gruelling five setters at Melbourne Park.
"I didn't feel prepared for playing in this big event. My first Grand Slam after one year, five-set matches, is very tough," said Del Potro, who memorably won the US Open in 2009 at the age of 20 when he defeated Roger Federer.
"It could be dangerous for my wrist. I think it was a tough decision, but could be a smart decision if I want to stay healthy and play for the whole year."
Del Potro also had a long layoff in 2010, when he peaked at world No 4, stemming from an injury to his right wrist before bouncing back and breaking into the top five at the end of 2013.
He said playing in Sydney was the right thing to do and he was positive about his future, despite the latest setback as he looks to lift his ranking from 276.
"I'm looking forward for my future, for my career. I have to do what the doctor says but I'm still positive," he said.
"I want to play tennis. It doesn't matter how.
"After seeing my level in Sydney, I think if I in good shape and I'm healthy, without pain, I could be competitive again very soon."
As well as winning the US Open, the lanky right-handed Buenos Aires native has also reached the semi-finals of the French Open (2009) and Wimbledon (2013) as well as two Australian Open quarter-finals (2009, 2012).