Vidal has long been considered a doubt for Friday's clash after undergoing meniscus surgery in May, but came on as a 77th-minute substitute against Northern Ireland on Wednesday.
And Jorge Sampaoli's men were handed a further boost on Saturday after scans on the midfielder's knee only indicated inflammation in line with Vidal's planned recovery.
It remains to be seen whether the Juventus man will be fit enough to play against Australia in Cuiaba, but defender Rojas does not believe Vidal's presence will be crucial to their chances.
Asked about Vidal's prospective absence, Rojas replied: "This coaching staff has always taught us that the most important thing is the group, not the individual.
"The key is to defend the idea of the group. We will not give up on what the coach proposes.
"We will continue with our attacking game against Australia.
"It would be a mistake to change our footballing ideology. That will never happen."
