The referee from England's warm-up game has warned Wayne Rooney to "control his temper" or risk being sent off in the World Cup, which starts on Friday.Rooney was booked in Monday's 3-0 win over Platinum Stars and match official Jeff Selogilwe claimed the striker insulted him with "vulgar language".Selogilwe said: "He must learn to control his temper. He could get sent off in the World Cup."Rooney, 24, apologised after the game and gave the referee his shirt.Ahead of the match against Platinum Stars, England vice-captain Frank Lampard had warned his team-mates that discipline on the field will be a key factor if they are to be successful in the tournament.He also rejected suggestions that Rooney, who was was sent off for stamping on Portugal defender Ricardo Carvalho at the last World Cup in 2006, might lose his cool again."Wayne has matured a lot as a player over the last few years as we all know, so I don't see that one happening," he stated."It is so important to have 11 men on the pitch because small details are so important and when you lose a player it can change anything."However, South African referee Selogilwe took a different view after Rooney came on for the second half in Monday's warm-up match.England's World Cup campaign gets under way with a Group C match against the United States on Saturday and Selogilwe conceded he was disappointed with the Manchester United player's attitude.He added: "He is a good player when you see him on the TV but when you see him on the pitch, he just keeps on insulting the referees."To me, it looks like Rooney insults people and fouls other players. If he insults a referee like me then he will use that vulgar language to other referees as well. I was very disappointed in Rooney because he is my favourite player."Rooney made a goal for Joe Cole and scored himself late on after Jermain Defoe had given Fabio Capello's side an early lead against the local side.However, Rooney also appeared to become embroiled in a second-half spat with Platinum Stars' Kagiso Senamela before being booked for dissent.Tottenham striker Defoe, who scored the opener on Monday, said he did not see Rooney's temperament as an issue."If under control, I think Wayne's temper is a good thing," he commented. "He has that fire in his belly. If you take that away from him then he won't be the same player."Source: BBC