Veteran Serbian coach Radomir Antic has earmarked Harry Kewell as the biggest danger to his side when they take on the Socceroos in next year's World Cup in South Africa.Kewell was on target for Turkish side Galatasaray again at the weekend with his strike securing a 3-2 win over Antalyaspor, whose second goal was scored by Kewell's international teammate Mile Jedinak.And Antic, whose side meet Australia in a Group D clash in Nelspruit on June 23, believes Kewell will be the key to the Socceroos' chances of victory.The 61-year-old, who coached Barcelona, Real Madrid and Atletico Madrid in a successful 16-year spell in Spain, admitted he had tried to sign the former Leeds United and Liverpool playmaker during his time in La Liga."I saw Kewell play two, three games," said Antic when asked to identify Australia's strong points."Five or six years ago I looked into signing Kewell when I was in Spain."I think he's a great player with a great career and I have time, five, six months to learn a lot more about all the players from Australia."Antic also underlined his admiration for Socceroos counterpart Pim Verbeek and his side, who many regard as the weakest team in a competitive group that also includes Germany and Ghana."I have a lot of respect, especially for national coach Pim Verbeek," said Antic."I have a lot of respect of the Dutch way to play football."They conceded just one goal in qualification and it will be a very, very tough game for us."Serbia present something of an unknown challenge for Australia.The Socceroos have never met the Balkan nation at senior level, with the former regional republic of Yugoslavia only gaining absolute independence in 2006 after Montenegro opted to break away from its union with the Serbs.Australia's last appearance against a Yugoslavian representation was in 1988, when a side featuring Graham Arnold, Frank Farina, David Mitchell and Robbie Slater helped secure a 1-0 upset at the Seoul Olympics.Much is expected of a Serbian side that contains Manchester United defender Nemanja Vidic, Inter Milan midfielder Dejan Stankovic and prolific Standard Liege striker Milan Jovanovic, who scored five goals in qualifying."For us, its a new experience, it's the first time we are going to the World Cup as Serbia and people are expecting a lot from us," said Antic."We have a good contact with the people in Serbia, the way that we play the football and that's one of the reasons were looking very much forward to start the World Cup."