Late change: Steve Smith to miss third Ashes Test

Usman Khawaja is set to earn a reprieve and come back into Australia's side.

The hosts can wrap up the series with victory in Adelaide, but the absence of Smith comes as a huge blow.

The 36-year-old remains Australia's most reliable batter, with scores of 61 not out and 23 in the eight-wicket win in Brisbane earlier this month.

He missed training on Monday and, while he was back in the nets Tuesday, Smith was spotted looking disappointed after a chat with team staff on Wednesday morning.

Khawaja was then congratulated by teammates.

The 38-year-old's recall comes just one day after his Test career appeared over, when left out of the side despite recovering from back spasms.

He will likely bat in the middle order with Australia keen to keep Travis Head and Jake Weatherald at the top.