what a joke,how many times in a row did Adam Docker from the riff get knocked out in games ,but he still backed up,have they been penalised,this rule can also be abussed,I watched a game earlier this year involving the rorters,Maria got hit hard in a tackle,stayed down about 20 seconds,trainer came on,then he goes off,he didnt even looked concussed,free interchange right there,and the hit he got wasnt that hard either