Ashes: Australia's prime minister Scott Morrison's anger at 'total foul' of fans booing Steve Smith

Fans jeered batsman during concussion drama

Australia's Steve Smith received some boos during Saturday's concussion drama at Lord's. Reuters

Australia's prime minister has criticised England fans for booing Steve Smith after he was felled by a bouncer during the second Ashes Test.

There was widespread concern when Smith suffered a horrifying blow to the neck from a fierce Jofra Archer delivery on day four at Lord's.

The batsman was persuaded to retire hurt after receiving treatment in the middle but returned to complete his innings little more than 40 minutes later.

On each occasion he was applauded warmly by most in attendance but there were some who jeered, a common reaction since his return from a 12-month ban for his role in the ball-tampering scandal in South Africa in March 2018 that rocked Australian cricket.

Smith was then ruled out of the final day of the Test with delayed onset concussion and Marnus Labuschagne became the first substitute batsman in the sport's history.

Writing on Facebook on Monday, prime minister Scott Morrison called it a "total foul" that Smith had been the subject of jeers from the crowds - and urged the 30-year-old to silence his critics by "bringing home the Ashes".

"A draw for the second test but it was a total Ashes foul for the crowd at Lords to boo Steve Smith," Mr Morrison said.

"His performance on the pitch during his return to Test Match cricket in the UK demands nothing other than respect.

"He's a champion and has handled the events of the past year with a real humility.

"I'm extremely proud of Steve Smith, and it's not just because he comes from the Shire," a reference to the region south of Sydney where Smith is from and which Morrison represents in parliament.

He added: "The crowd could learn a thing or two from Steve Smith and I look forward to him answering his hecklers with bat and ball in hand to bring home the Ashes."

Meanwhile, Cricket Australia's sports medicine manager warned against an overreaction to players suffering head knocks after Smith was allowed to return to the field before being ruled out the following day.

After the incident, Smith passed all the on and off-field testing protocols but woke up on Sunday morning reporting a headache and feelings of grogginess; he is now a doubt for the third Test in Leeds.

Follow-up tests showed his results had deteriorated and Cricket Australia became the first side to initiate the concussion substitute rules that were introduced by the International Cricket Council just this month, with Labuschagne being the first such replacement.

Speaking to reporters on Monday, Alex Kountouris said protocols had been followed correctly and that "about 30 per cent of concussions are delayed".

"We've got a protocol in place. Part of that process was to make a determination at the end and he clearly didn't have a concussion so we allowed him to go back on the field," he said.

"In this case, overnight or the next morning he developed some symptoms and when we did the testing again he didn't actually pass his concussion test."

He added: "The reality is at the time he didn't have a concussion.

"If we pulled every player out who had a head impact we'd be pulling out 80 per cent of players who don't have concussion so that would be an overreaction.

"It's pretty clear for us. We've got a doctor there. He is an expert in this field and trained to pick up even the minor signs of concussion.

"He was very confident that Steve was fine. He didn't have concussion at the time so he was allowed to play.

"If we'd left him out of the game we would have been leaving him out for no reason other than what we saw on the field."

Cricket Australia said Smith had a "precautionary scan" on his neck on Sunday, which cleared him of any structural damage.

He returned to the team hotel to rest after the scan and "will continue to be reviewed on an ongoing basis", CA added.

The third Test at Headingley starts on Thursday. If Australia win there then they will retain the Ashes and be assured of avoiding defeat in a series in England for the first time since 2001.