Turning injuries on is a great idea! Real life sports often depend heavily on having depth pieces step in and play big roles when players go down. I feel like most teams that win championships have some cool story about a guy who either barely cracked the roster or was brought in from outside to fill a hole created by injury and ends up making a big splash to help push the team over the edge. OBVIOUSLY that will translate well to sim leagues and absolutely no one will get fucked by injuries in a way that makes them leave the league or lose interest. No chance.