Warner and Smith have stated that neck guards on helmet make them uncomfortable.
CA will make wearing neck protection at international training and matches mandatory via a change to its clothing and equipment regulations, the report said.
The update in regulations came a week after Cameron Green was hit on the back of the neck by Kagiso Rabada but was saved from a serious injury thanks to the neck guard fixed to his helmet and substituted out of the first ODI against South Africa with a concussion at Bloemfontein on September 7.
However, this rule change might have an effect on batters like Steve Smith and David Warner, who have resisted using the neck guards since their introduction in 2015. Usman Khawaja also does not currently wear the protectors when batting.
The recommendation to wear neck guards on the back of the helmet came from CA following the tragic death of Phillip Hughes but several veteran players have been reluctant to take them up.
Smith had earlier said the neck guards made him "feel claustrophobic". He was not wearing a neck guard when struck by a Jofra Archer delivery at Lord's in the 2019 Ashes.
On the other hand, Warner said in 2016 that he does "not and will not wear" one because it "digs into" his neck and is an "uncomfortable distraction".
Australia international players will now be required to wear neckguards during both home and away matches.
However, the report suggested that though international umpires won't enforce the regulation like in domestic cricket, Australian players might be sanctioned under CA's code of conduct for a breach of clothing and equipment regulations.
Among other changes, the CA has removed the COVID-19 substitute rule from its playing conditions in line with the ICC doing the same.
(PTI inputs)