I had always reasoned on why a club would buy players and only a first set of eleven regularly gets playing time. Psychologically, it weaken other members of a team knowing that they are regarded as second fiddles. Like in all other facets of life talents not put to use in time gets diminished. Same is also applicable to football.

Now to the question on how many subs are to be substituted in a match? Well, football itself, has evolved with time, I see nothing wrong whatsoever to substitute up to seven players in match. It will automatically give hope to other players bench to give their all, knowing that there's a possibility of them playing anyways.

Secondly, in my opinion, it may give the club an overall view of the talents in the team. The constant injuries sometimes are caused because of overuse of player. I absolutely think seven substitutions will be ideal.