I didn't come here for the money, says injured Almagro

Almagro lasted 23 minutes of his game against France's Jeremy Chardy when, serving at 4-0 down, he double-faulted, walked back to his chair and conceded the match.

Given his brief presence in the tournament, some have suggested that the only reason he made the match at all was to pick up some tournament prize money. However, the 31-year-old, a quarter-finalist at Melbourne Park in 2013, cited his career earnings of more than $10 million as proof that his motivation was not the money.

"I went to court because I think I can play," he told reporters. "I was top 10, I have more than $10 million. I'm not going to play for $50,000. It is not the reason."

Almagro said he had undergone an MRI scan on his injured calf last week but had not felt the injury in training in Melbourne so decided to play his opening match.

"I was trying to play during the week," he added. "It was tough. I did an MRI and the result wasn't good. That's it. I couldn't play. I felt the problem again on court and I had to retire."