what is the common injury faced by the players?
Bleeding
Rugby union
 bleeding 
who was the irishman who founded new zealand's most english city David Gallaher where was he from? Ramelton, County Donegal, Ireland what was his career? He was a rugby union footballer best remembered as the captain of the "Original All Blacks". how is this game played? It  is a full contact team sport based on running with the ball in hand.  A game is played between two teams of 15 players using an oval-shaped ball on a rectangular field called a pitch.
wiki:25621749
Rugby union [SEP] Replacements and substitutions
During the match, players may be replaced (for injury) or substituted (for tactical reasons). A player who has been replaced may not rejoin play unless he was temporarily replaced to have bleeding controlled; a player who has been substituted may return temporarily, to replace a player who has a blood injury or has suffered a concussion, or permanently, if he is replacing a front-row forward. In international matches, eight replacements are allowed; in domestic or cross-border tournaments, at the discretion of the responsible national union(s), the number of replacements may be nominated to a maximum of eight, of whom three must be sufficiently trained and experienced to provide cover for the three front row positions.