The last year I coached softball in rec league. I had a player refusing to try sliding at practice. So I politely ask her to get her bat bag and go home. So she got her bag and went to her car crying. Well here comes Dad I explained all of our players were going to try to learn skills needed to play the game. Dad says since she was a bigger girl she wouldn’t be sliding anyway. I ask him to take it up with the rec league board. Yes they called and told me I had to let her play so next practice about half way through practice and I haven’t hit her 1 ball. She went to the dugout got her bat bag and was walking off. I ran over to her and ask if she was willing to try the skills I’m teaching the next time we were working on sliding. She agreed and we never had another problem and she did try sliding later. If she had refused I would just let her go. A bad attitude can kill a team. I feel it’s better to have a talk with parents at beginning of team to let them know I’m not going to argue and I coach the best I can. If you get a know it all parent ask them to pitch batting practice in the cage tell them to only throw strikes. I swear that’s the hardest thing for a parent to do. It will shut them up.