Ghana striker Asamoah Gyan admits he is heading into one of his toughest personal duels when he lines up against a Serbia defence manned by Manchester United's Nemanja Vidic.Gyan is likely to play as the lone man upfront for Milovan Rajevac's team against Serbia defence that includes the United hard man and the impressive Branislav Ivanovic of Chelsea."It's not gonna be easy, Gyan said of the challenge. They have one of the best defence and I think it will be quiet a battle against him (Vidic). But the coach will dictate our tactics and then hopefully we can get a good result."Gyan struck Ghana's first ever goal at the World Cup against Czech Republic four years ago in Germany and will be looking to get on the score sheet again in South Africa even though he insists the team comes first."We are playing as a team although everyone expects me to score goals. If the opportunity to score comes, I will take it but first it is team work. I will make sure i will do my best and help the team win."Source: Kickoff.com