Lyon suffered a calf injury on the second day which is all but certain to rule him out of the tour, but he hobbled to the crease at the end of Australia's second innings, adding 15 runs for the final wicket with Mitchell Starc.

Commentating on Sky Sports, Kevin Pietersen raised the question of whether it could have been done for the potential of getting Lyon subbed out of the game which can only happen through concussion or Covid-19.

"Imagine if he [Lyon] had been hit on the head and got concussion, he'd have got a like-for-like replacement and a world-class spinner [Todd Murphy], based on how he performed in India, it gives food for thought," Pietersen said.

When asked a broader question about whether cricket should introduce substitutes for a variety of injuries to avoid a team being a player down, Lyon referenced the death of Hughes who was struck by a bouncer while playing for New South Wales in late 2014.

"Test cricket's been around a lot longer than I have and injuries are part of the game," he said. "I have heard comments that I only went out there to get hit in the head but I'm really against that. I have lost one of my mates due to being hit in the head so I think that's a really poor conversation being had, if I'm honest with you."

Lyon, who described his injury as a "decent tear", will have further conversations with Australia's medical team on Sunday about his future on the tour but is resigned to an extended period on the sidelines for the first time since he made his Test debut in 2011. This injury has come during his 100th consecutive Test and he sits on 496 wickets.

He admitted it had been an emotional few days but was determined to help Australia in any way he could which is why he came to the crease.

"I have been absolutely shattered," he said. "I have been in tears, I have been upset, I have been hurting. That shows this team means everything to me. And I will start this rehab journey now to get back and play my role and keep loving what I am able to do.

"After doing this for 13 years and not missing a day of school, if you can put it like that, it's going to be challenging. It's going to be different. It's a different challenge. But we always look forward to different challenges and trying to find a way to get better."

Lyon, who had to wait in the Long Room when the eighth wicket fell to avoid being timed out, said that Pat Cummins and Andrew McDonald had been reluctant about the idea of him batting, but he believed any runs added could prove vital.

"I knew the risks," he said. "But the way I look at it… I'll do anything for this team. You never know how big a 15-run partnership can be in an Ashes series. I'm proud of myself for going out there and doing that. I'll do it again and again and again. I love this team. I love playing cricket for Australia. And if I can keep playing my role and help out my team-mates I'll do that."