Jofra Archer sent both the batsmen back to the pavilion.Soon after Cameron Bancroft (16) was also dismissed leaving Australia in a spot of bother at 47/3. Saw made the decision to take Smith from the field on Saturday and, after a series of tests indicated no signs of concussion, allowed the batsman to continue his innings.
Match referee Ranjan Madugalle has approved Australia's application for Labuschagne to serve as a like-for-like replacement for Smith.
It was then announced further tests found delayed onset concussion and Smith was replaced by Marnus Labuschagne for day five.
It was a similar delivery from Archer that hit Smith on day four.
With the third Test starting at Headingley in Leeds on Thursday, time maybe Smith's biggest enemy.
"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", said Morrison. "I woke up feeling a little bit groggy and with a headache again".
"The neck didn't have any real pain [on Saturday] when I touched it or when anyone else touched it".
"I find it a little bit different to what I'm used to".
"I'm hopeful I will be available for that Test match".
"It's certainly an area of concern - concussion, and I want to be 100 per cent fit", Smith was quoted as saying by BBC Sport". "There are a few tests I'll have to tick off and time will tell", he added.
Steve Smith is reconsidering his refusal to use a neck guard while batting, even though the talented batsman feels "claustrophobic" when the attachment is clipped onto his helmet. "We just need to monitor them", he said. "Which was fine by me, because my eyes were going a bit as it was, so I reckon I would have told them to get away in no uncertain terms anyway!" Upon discussions with the doctor and the team coach, they were both happy and I was comfortable.
Smith complained of headaches later Saturday and was ruled out of the remainder of the match on Sunday after displaying concussion symptoms.
"I'd obviously love to be out there trying to keep performing and try and help Australia win another Test match, but I think the right decision has been made".
"Steve's fitness will be assessed on an ongoing basis". "Steve will undergo a precautionary scan on his neck on Sunday", the CA statement said.
The runs continued to flow, and after Stokes got through to his hundred, he and Bairstow flayed the ball around the ground for another over before the declaration to leave England with an hour to bowl at Australia before tea. "I still finished my net, had a few more balls and then walked out and said "righto, now it's time to focus and get your mind".
"A player is no longer under pressure to take the field when he or she displays symptoms of concussion and a side is not disadvantaged having lost a player to a blow to the head or neck".