I think it would be useless change... You see it from the side that your player injured. What if you train a player and he will make the foul and he will be kicked out of the game?Or your best player during a rival game. Only disadvantages this option
In real life it is common for a player to be ejected for a flagrant foul... so if your trainee is injured by a flagrant foul it is ok for him to leave the game and to be sidelined for weeks while nothing happens to the aggressive player who causes the injury? I don't really get this logic.
I'm an advocate for injuries to be removed from this game, but if they remain I don't see why this suggestion (penalising the aggressive player as well) couldn't be implemented. It actually makes a lot of sense. Yeah, it sucks to have your cherished player unavailable for ages, but it also sucks to have him sidelined because of the actions of another player. It should suck both ways.