Australia's star midfielder Mile Jedinak said on Tuesday he is confident of being fit for the 2014 FIFA World Cup Brazil™ despite picking up a groin injury playing for his club Crystal Palace.

Jedinak, who is expected to be named national captain on Wednesday when Ange Postecoglou announces his squad for Brazil, said he expected to be sidelined for three weeks but the results of a scan were "as good as I could have hoped for".

"It's a little bit sore and it's going to mean I miss a couple of weeks or so, but I just got the scan results back and honestly the news is probably as good as I could have hoped for," he told Sydney newspaper The Daily Telegraph.

"The doctors say I'm looking at two to three weeks, so I have to concentrate now on doing everything in my power to be ready in that timeframe."

Jedinak said the injury "came on all of a sudden" in the game against Fulham on Sunday and he was "seriously glad" to be substituted after 59 minutes.

The 29-year-old may delay his return to Australia to join the Socceroos' training camp starting on Thursday.

"I'm definitely coming back to Australia at some point in the next couple of weeks; the club and the national team staff are just working out the details now of exactly what the rehab will be," Jedinak said.

The injury sent a scare through the World Cup squad, with Australia in one of the tournament's toughest groups. They play their first game against Chile at Cuiaba on 13 June.

Jedinak told the newspaper he had not heard anything about wearing the captain's armband, but said it would be a "huge honour" if he was handed the role by Postecoglou.

"When the armband is given to you, the feeling in your head is just wow - you think of the people who have had the honour of captaining the side before, the characters, and it's a special feeling," he said.