Rugby union is trialling a new protocol called the Pitch-Side Concussion Assessment (PSCA) to try and deal with the problem of concussion.

But critics, including Dr Barry O'Driscoll, the uncle of Brian and a former Ireland international himself, believe the system means concussed players are being allowed back onto the pitch.

The "big hit" culture of the modern game is forcing rugby's bosses, players and fans to confront head-on some very uncomfortable questions.