Manchester United manager David Moyes says he thinks retrospective punishment should be used as part of the effort to stop players from diving. Moyes confirmed that he has spoken to United winger Ashley Young, who was booked for simulation during the 2-0 home victory over Crystal Palace on Saturday. Young's booking has prompted much debate about the diving issue and Palace chairman Steve Parish thinks offenders should be sent off. And Moyes, who has always been a stern critic of diving, says he has left Young in no doubt about his feelings on the subject. But he also stressed that the diving incident had been dealt with correctly at the weekend by referee Jon Moss. "I've had a word with him (Young) privately and, as I said after the game, I've said for many years we should have retrospective video for diving," said Moyes. "I think that would help referees no end, as it's really difficult at times. It doesn't change my views, whether I'm at Everton or whether I'm at Manchester United. "We can make up all the things we like about punishment but the rules are there and the referees have got the rules they have to abide by. "The referee on Saturday did what he had to do, he gave him a yellow card. "The referee got it correct and he gave the punishment for it, so I don't see why the debate should go on any longer."