So in today's game oranges player is tacked with a fair bit of force due to the comparative size of his opponent but in my mind 100% fairly challenged. The ball trickles out for a goal kick after some shielding and then I see the orange player is on the ground, thumping the turf and clutching his knee. I wave on the coach/physio to assess the injury and while the player is still down he is questioning my decisions, calling the tackle a joke along with all my calls for the day. Had already initiated the stepped approach for this particular player and this was the last straw. Coach tells his player to shut up then says there will have to be a substitution. I say just one moment and yellow card the player for dissent, the player is on the ground still...I then allow him to leave the field (was only 5 yards or so from the touchline) to be replaced by another player. Only the injured lad had any arguments about my actions really but did I do this correctly? Often I see referees on TV waiting until the player gets up from his cruncher of a challenge to get booked but this felt different, I know it was a clear booking for dissent but have no idea if procedure was right or not!