Liverpool's England captain Steven Gerrard has warned Wayne Rooney against swearing at World Cup referees.
Gerrard is warning his team-mates not to get caught in the trap.
"You don't swear at them, do you?" he said.
"That's the answer to that. In this day and age I think it's important to show the referees some respect. You don't use any language because then you'll be booked and the whole team suffers.
"You don't want to fall into that trap."
Rooney's temper has been widely discussed, but Gerrard expects the Manchester United forward to be able to handle any goading he may face.
"I'm not sure whether he'll be targeted, we'll wait and see," he said. "Wayne's experienced enough now to deal with it if he is.
"Wayne understands we need him on the pitch, he's a very important player, and every player has been warned by the manager and coaching staff to channel their frustration in the right way and not get involved with the referees or with any silly challenges.
"We've had experience of losing big players at important times and we need to keep everyone on the pitch."