'Absolute load of rubbish' - Australia coach Justin Langer hits back at Steve Smith criticism

Australia coach Justin Langer has backed Tim Paine's leadership and described criticism of Steve Smith as "rubbish" after the batsman faced accusations of gamesmanship in the wake of the third Test against India.

Captain Paine has been under fire from former players and pundits for abusive sledging of Ravichandran Ashwin as the India spinner batted on the tense final day of the draw at the Sydney Cricket Ground.

Langer said Paine, who apologised for his conduct on Tuesday, had fallen short of the team's standards in Sydney but had barely put a "hair out of place" in nearly three years leading the team.

"He has been outstanding as the Australian captain in everything he does," said Langer. "He had a frustrating day. We've got to cut him some slack, surely. (He's an) outstanding leader and will continue to be for some time to come yet ... He has my 100 per cent support."

Smith has been under scrutiny after video footage from the stump camera in Sydney showed him dragging his boot across the batting crease as Australia tried to bowl India out on day five.

Former players accused him of trying to erase Rishabh Pant's guard but Smith said he was just marking centre as he would normally do if he was batting. Langer refuted any suggestion Smith was seeking an advantage.

"Absolute load of rubbish. If anyone knows Steve Smith, he's a bit quirky and we've all laughed about it for the past couple of years," he said. "Anyone who suggests for one millisecond he was trying to do something untoward, they are way out of line. Give me a break."

The series is level at 1-1 heading into the final Test in Brisbane on Friday.

Langer said opening batsman David Warner, who made five and 13 in Sydney and was hampered by his groin injury, would be fit to play at the Gabba. However, rookie opener Will Pucovski remained a doubt after injuring his shoulder in the field in Sydney.

"We’re really hopeful he’ll get up, if he doesn’t the obvious thing will be Marcus Harris will come in to open," said Langer.