This is a very good discussion topic and one that players, coaches, parents, and even refs can share. As a player, I never want play to stop. As a parent, I would like to see my player protected. As a referee, I have to evaluate each situation individually. I believe the correct approach to stopping play is "it depends". In the AYSO, they want referees to stop play regardless, and thus the old "take a knee" comes in to play. For more competitive play, one must weigh the safety for the player, and preserving the game. The default is player safety comes before the game. Period. However with soccer, because it is best viewed without interruption, it is a delicate balance. One thing as a referee I need to be aware is that if I make the wrong decision, there could be a life at stake. A quick answer to "are you ok?" usually tells me a lot. There are situations where the referee should stop play, should not stop play, must stop play and must not stop play. The "should" is sort of the discretion of the referee, for the good of the player and game. The stoppage of play is a referee prerogative, not the players. Law 5 lists referee powers and duties. The referee has the power to stop the game, and the duty to protect players. If the referee in the above example stopped play, one thing to determine in the thought process, "did the player respond?", "is there visible signs of blood and is it a danger to the other players? Referees do not have medical training however this year's Point of Emphasis by TSSAA is the concussion. Blood is another issue. So in the above example, the referee could have used his discretionary power to ascertain whether the player hit in the face with the ball either was bleeding or needed attention. One thing referees are very aware of are players feigning injury behind play to stop an attack.