How Many Players on a Football Team
In American football, there can only be 11 players from each team on the field at one time. There are usually about 45 players that are cycled through each game, and a team can have no more than 53 players total.
There is also a stipulation that a team may only carry 45 players on its game day roster, so the team must decide each week on which 8 players will be inactive, or 7 if they carry a 3rd QB
Teams may have up to 53 players on roster, of which 45 may play in each game. There can be 11 on the field at one time. There is no limit on substitutions.
Teams may have up to 18 players, of which 11 can be on the field at one time. Only three substitutes may be used per game.
Australian Rules Football
There are 22 players on a team, of which 18 may be on the field at any time. There is no limit on substitutions.
There may be up to 30 players on a team, only 15 of which may take the field at any time. Only 5 substitutes can be made per game.
Rugby Football – League
There may be up to 17 players in a team, of which 13 may be on the field. There is no limit on substitutions.
Rugby Football – Union
There are 22 players on a team, of which 15 may be on the field at any time.
UK Football – FIFA, UEFA
11 Players can play in a football match, 10 of which play outfield and 1 as the goalkeeper. 24 Players can be selected as the squad for the match. Depending on the league and country, a different amount of substitutions can be made during the match.
In the UK, unless special rules are applied, you are allowed 3 substitutions during the match. Exceptions can be made but only if the player is seriously injured.
Of course, red cards mean the end of the match for a player, and they cannot be replaced. If the number of players on the field gets too low, the referee can abandon the match at any time to be replayed later on.