The Republic of Ireland and Sunderland midfielder suffered the injury in a reckless tackle by Bilong - a former Cameroon international - in a 2-1 friendly defeat of Hiroshima on Saturday.
All I can do is let the swelling go down and hope that I can be right for
It was at first feared that McAteer had damaged ligaments and his World Cup would be over.
But the scans revealed nothing more than bad bruising on the bone.
Therefore the 30-year-old hopes to win his 48th cap in Saturday's crucial Group E opener.
"I was worried that I might have a serious injury but that is not now the case," said McAteer.
"All I can do is let the swelling go down and hope that I can be right for Saturday with a mixture of rest and treatment."
Manager Mick McCarthy said: "Jason's got a smile back on his face which is always a good sign."
Steven Reid is on standby but on a brighter note both Kevin Kilbane and Ian Harte, who also picked up foot injuries in the game, are expected to be fit.
Meanwhile, McAteer is upset that Roy Keane will not be playing in the World Cup - but he insists he does not understand the departed skipper's rage.
He is at pains to understand the anger Keane unleashed on manager Mick McCarthy at the Irish squad's now infamous team meeting on Wednesday.
"Roy is going home and I am gutted," McAteer said in his Irish Sunday Independent World Cup diary.
I am not going to repeat what he said to Mick McCarthy but he was way offside
"I want him to stay. He is one of the best footballers in the world and I love playing with him.
"Everything is black or white with Roy, there is no such colour as grey.
"He thought what had happened during training was wrong and said so, and I admire him for that.
"He wants the best for everyone in the squad but I do not always understand his rage.
"When he got on the bus after that training session and started staring at the roof I knew something was wrong."
The row which erupted between Keane and McCarthy reminded McAteer of a similar argument he had had with his former manager Graeme Souness at Blackburn Rovers.
"He almost ruined my career and I cannot help but despise him for it.
"We had an argument one day in his office which, although not as vicious, reminded me of the one Mick and Roy had," he said of Souness.