UEFA have encouraged referees to provide greater protection to players ahead of the beginning of the Champions League knockout stages this week.
Giving better protection to players is a theme that has been taken up by several managers this season.
Pep Guardiola has been particularly vocal on the issue, and - who administer referees in England - to discuss several tackles on their players they deem to be unacceptable.
Now UEFA`s chief refereeing officer Pierluigi Collina has added his opinion, saying: We need to have players playing, so they must be protected on the field.
We do not want situations where a player`s future is put in doubt because of serious injury caused by a challenge, whether it is intentional or unintentional.
Players must understand they have to respect their opponents and show the same positive behaviour to them they would want to receive themselves.
UEFA have also asked their officials to punish players who deny obvious goal-scoring opportunities, as well as criticising players who surround referees.
Collina added: When I see mobbing of a referee, it`s something that is not acceptable - this is not the message that we want the game to convey.
Football is a beautiful game, and we want it to stay that way.