The Chelsea player was left out of the Confederations Cup squad earlier this year, with Scolari wanting two defensive midfielders who do not have a tendency to charge upfield.
There were also Brazilian media reports that Ramires had fallen out of favour because he had reported late before the friendly against England in London in February but he has now been given a new chance.
"The player had a problem, we understood that and he will have a chance to be part of the group," Scolari told reporters.
"He will have to show that, technically, he is good enough. We have created a healthy atmosphere here and we want to carry that on until the World Cup.
"The most important thing is the national team."
Fullback Maicon, who fell out of favour after the 2010 World Cup, was also recalled.
"We have been observing him since he was at Manchester City and the information is that he is doing really well," Scolari said. "His experience is also important."
Maicon has since joined AS Roma.
Elsewhere, Scolari largely kept the core of the squad who won the Confederations Cup in June.
The European-based players face a marathon for the two games as Brazil, who will stage the 2014 World Cup, host Australia in Brasilia on September 7 and then play Portugal in Boston three days later.