It's not just about time wasting though is it. That can and does get added on when taking the p155. Eg a minute to take a goal kick. It's more about teams taking away the advantage. Slowing play down to reorganise. As far as I'm concerned. Unless it's a serious injury and not just imitation cramp. Or a broken fingernail. Play goes on. If a player goes down for no apparent reason other than bringing the physio on to rub his toes. Send him off for 5 minutes to let him recover the little darling. None of this kicking the ball out of play for the opposition player pulling a fast one. Let the referee decide. None of this throwing the ball back to the opposition bo77ox. The most stupid rule. Is if an injured player fouled by the opposition is genuinely injured. He's the silly bugger who has to go off to be waved back on. Bonkers. make the offender go off ffs. Sin bin if necessary. Especially if the tackle led to him getting booked.