A playing squad for each official competition game comprises 23 players and only 15 players can start. Rugby does not have offensive, defensive or special teams like football – all players on the field are playing offense AND defense so there are no stoppages to allow for team changes as in football. In rugby the jersey number belongs to the position on the field and not the player. Starting players are allocated the first 15 jerseys and the 8 substitute players form the substitution bench for that game. The numbers are for the following positions:
1, 3 Props x 2
2 Hooker
4, 5 Locks x 2
6 Blind side Flanker
7 Open side Flanker
8 No. 8
9 Scrumhalf
10 Flyhalf
11, 14 Wing (11 – left, 14 – right)
12 Inside Center
13 Outside Center
15 Full Back
16 to 23 Subs: The jersey numbers for the substitute players are not allocated to a particular position as the coaches are required to select the playing squad of 23 prior to the start of any competition game and write them down on the AZ Rugby Union’s official game report.
Substitutions are made at any time at the discretion of the head coach unless a referee asks a player to leave the field for blood. In the case of a blood substitution, the player sent off can return to play. In the case of a normal substitution, the substituted player cannot return to the field in the half they are playing in except in unusual circumstances (e.g. if the number of key players in the scrum drops below a certain threshold). It is common for coaches to not use all substitute players and the coaches decide who to have on the bench to be back up to particular starting players. This means that usually 75%+ of the starting players will play the entire game. It is why fitness is such a key attribute for success in rugby.