The Head Injury Assessment introduced by the Six Nations for players injured in a game is missing one important piece of information. The Assessment has no baseline. If a rugby player is not tested out of season (so a brain scan) when he or she is injured the doctor at pitch side has no reference point.
Until there is a baseline players who have had an injury to the head in a game should go off and stay off. This is for their long term good.
I hope World Rugby will bring in baseline testing in time for RWC19 in Japan.
Former England international and Founder of BRAIN