So in the 2014 ATP Tour finals, Milos Raonic has pulled out with an injury but he is being replaced by David Ferrer.
This seems rather unprecedented. Tennis (singles) is not really a team sport - it's not like football where one player can get injured in the middle of the game and be replaced by another player. Even in other tennis tournaments, if a player injures himself, he can't just get someone to replace him for the rest of the tournament.
So aside from wanting to know why he would be replaced, I would like to know what the competition rules are now. Raonic has already played two matches - Ferrer only has one left in the group stage. Granted Raonic lost both his matches so isn't able to qualify for the semi final anyway, but if he had won these matches, does Ferrer inherit these wins? If he doesn't, what's the point in Ferrer even playing since there is no chance for him to reach the semi finals with playing only one game.