A brutal blow to Steve Smith's exposed neck has reignited debate over the use of neck guards in cricket, which could potentially become mandatory in Australia as soon as next year.
Smith wasn't wearing a StemGuard, the protective attachment designed by helmet manufacturer Masuri in the aftermath of Phillip Hughes' tragic death in 2014.
Smith never has during a match.
The former skipper tried using the clip-on attachment in the nets when it was launched in 2015 but felt the guard was uncomfortable and irritating.
For somebody as eccentric as the unique batsman, whose quirks include taping his shoelaces to his socks so they don't serve as an unsightly distraction, it was always going to be a hard sell.
Smith's scare, having hit the deck after a rocket delivered by express paceman Jofra Archer struck him flush on the neck at Lord's, may prompt the 30-year-old to revisit his stance.
The broader question is whether players should be forced to wear neck guards, made of plastic and foam, when they don a helmet.
AAP understands Cricket Australia (CA) is likely to review ongoing research about the efficacy of the guards in 2020, when a change to its policy is expected to be given strong consideration.
CA's head and trauma policy for 2019-20 was rolled out on July 1, without any major changes, and lists the use of neck guards as "recommended" but not mandatory.
The governing body has been a pacesetter regarding head knocks in cricket.
CA introduced concussion substitutes domestically in 2016 then successfully lobbied the International Cricket Council to make the same change at the highest level.
"I wouldn't be surprised if they (neck protectors) become mandatory in the future," Australia coach Justin Langer said.
"I didn't realise they weren't mandatory until today.
"It'll get talked about again. I know they came in after the tragedy of Hughesy.
"He (Smith) might rethink it now after seeing what happened today."
The issue was covered in the findings of NSW state coroner Michael Barnes into the death of Hughes, released in 2016.
Barnes recommended CA and helmet manufacturers continue to work on developing a neck guard that is comfortable and provides better protection, with a view to it becoming mandatory.
Barnes also made it clear a neck guard would have been unlikely to prevent the death of Hughes.
David Warner noted in 2016 he does "not and will not wear" a neck guard because it "digs into my neck, it is uncomfortable and is a distraction".
Manufacturers have worked hard to improve the design in recent years.
Sri Lanka legend Kumar Sangakkara, incoming president of the powerful Marylebone Cricket Club (MCC) and one of the first players to use a StemGuard, argued neck protection should become mandatory "sooner rather than later".