Brazil team doctor Jose Luiz Runco said Elano was suffering a bone bruise, the result of a crunching tackle he received during Brazil's second group game against Ivory Coast on June 20.
"He can walk and run without changing direction, the problem is the impact, when he puts weight on it," Runco told reporters. "The bone is swollen inside, hence the name.
"The treatment is to avoid impact, he can work in a swimming pool and on the exercise bike.
"He could be better in a few days, a week or a month. We still hope he can play next week but I can't say that categorically. He is working intensely so we have to see if nature can give a helping hand."
Brazil face the Dutch in Port Elizabeth on Friday.
Elano had initially shown signs of improvement and had hoped to play Monday against Chile.
But he felt discomfort on the eve of the match, being replaced by Dani Alves, and then limped out of a light practice on Tuesday after again feeling pain in the ankle.
Elano, who was taken off after the tackle in the second half of the Ivory Coast match, complained that the referee did not even give a foul.
"I told the referee that he didn't even give a free kick for a tackle which could have broken my leg," he said. "The same player then committed another heavy foul on Robinho for which he should have been sent off.
"They have to have another look at this type of violence because the people who are losing out are the ones who get injured.
"In our team, we have players with different characteristics but you never see our players committing a malicious tackle, in contrast to some of our opponents."
Elano, who scored in each of Brazil's first two games, said he was philosophical about what had happened.
"I feel sad occasionally but it passes quickly. I'm very optimistic. I've been through a lot of difficult things in my life and this is just another rock on my path.
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