The 27-year-old, who missed the drawn fourth Test with a bruised heel, took part in training on Tuesday afternoon.
Cummins believes that Starc will win his race to be fit for Wednesday's opener at the Sydney Cricket Ground, though with the series won and a four-Test tour of South Africa around the corner, the coaching staff may take a more cautious approach.
"He was running around without limping and it looked like he was bowling quickly," he told reporters. "He's pretty confident that he's going to play. Now it's about seeing how it recovers.
"If he didn't think he could get through the match, then he wouldn't play. He's played a lot of cricket now and he knows what he can get through."
Starc's replacement Jackson Bird posted figures of 0-108 in the fourth Test.