Why substitutions are made so late in games

My son asked me why managers wait so late to make all three substitutions in games. Great question.

Its quite simple really.A manager will make the appropriate change to strengthen his or her side.Replacing a weakening player for a stronger player. A Good manager will try to exploit a tactical weakness he or she may may see in an opponent.Conversely a substitution will be made to strengthen a side who may be exploited.

But one of the biggest reasons a manager will save his changes for so late is because if all three allowed substitutions are made too early in the game, say at the 50 minute mark or 60 minute mark and one of his players gets hurt then that team will be forced to play a man down for the remainder of the contest. No manager wants to get caught in such a scenario. So its a matter of rationing your players out while balancing out any tactical ambition you hoped to gain from changing a player. Too Early you run a risk of being caught short handed.Too late and any ambition of changing the face of a game could be wasted.