Referees have been reminded by Uefa to protect players by punishing serious fouls in European club competitions.
It comes after Manchester City boss Pep Guardiola urged English officials to take care of the game’s “artists” when Leroy Sane was injured in the FA Cup win at Cardiff in January.
Uefa has told referees they have a duty to “protect football’s image”.
“We need players playing, so they must be protected,” said Uefa’s chief refereeing officer Pierluigi Collina.
“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 is unintentional and the player making the challenge is taking a risk of causing injury.
“Players must understand that they have to respect their opponents and show the same positive behaviour to them that they would want to receive themselves.”
Europe’s governing body has also reminded referees not to tolerate being pressured into making decisions by groups of players.
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.”
Manchester City are at Basel and Tottenham go to Juventus in the first legs of their Champions League last-16 ties on Tuesday, while Liverpool go to Porto on Wednesday.
Chelsea and Manchester United play Barcelona and Sevilla respectively in their Champions League first legs next week.