[1] During the IRB 2011 Rugby World Cup, a study was conducted to determine the frequency and nature of the injuries sustained.
[4] In rugby league, blood replacement substitutions are enforced by the referee after he has noticed that a player is bleeding.
Fake blood injuries have been used for tactical benefit, to enable teams to withdraw a player they may wish to bring back on later.
A notable example was the "Bloodgate" incident, where Harlequins wing Tom Williams came off the field with what turned out to be a faked blood injury in order to facilitate a tactical substitution.
An investigation by the ERC and the RFU revealed that blood injuries had also been faked by Harlequins to enable tactical substitutions on four previous occasions.