I'm just new at T11 (at the end of 3rd season), but I've also seen my players very often injured this season. It was more often, than last season - and it seems, young player suffers more injures.
I also have a good player, which can't play 3 leaguegames because of 6 Yellow (=3x red) cards. That just happend...
I won a game vs 2 point better team, because he had "only" 15 players and his two top players were banned. It just happens...