JOHANNESBURG (Reuters) -- Coach Radomir Antic conceded the pressure of playing in its maiden tournament as an independent nation got to Serbia in the World Cup Group D opener against Ghana.

"We were far too nervous and we have to change our approach for the next two matches because we have to put some points on the board," he said.

A 1-0 defeat to Ghana means the Serbs now have to get a result against Germany, who walloped Australia 4-0 in the group's other match, if they are to stand a realistic chance of avoiding an early exit.

"Preparations for the game against Germany will start right away, we have learnt our lesson and we have to move on with our heads up," Antic said.

Serbia now have only four days to regroup before the clash with the Germans in Port Elizabeth but striker Nikola Zigic, who had hardly a sniff at goal on Sunday, was confident they could turn around their fortunes.

"We have to remain calm and keep a cool head because there are still six points for the taking in the remaining two matches and I am confident we can take them," he said.

"The defeat by Ghana was a bitter pill to swallow, we played well for 70 minutes and then got punished for not taking our chances, I missed a sitter myself while Ghana scored from out of the blue."

Aleksandar Lukovic, who was sent off midway trough the second half, added: "I let my team mates down but we have to pull our socks up because there is enough quality in this team to get going when the going gets tough."

Serbian players blamed the noisy vuvuzelas and the unpredictable World Cup ball for losing their focus and giving away a soft penalty in the closing stages, but it was their lack of bite up front and ineptitude in midfield that cost them.

Antic stuck to his preferred 4-4-2 formation with a flat midfield and two strikers but it turned out to be completely ineffective against a quicker and more flexible Ghanaian team.

The Serbians got trampled in midfield by opposition missing their most influential player, Michael Essien, and if they are to come away with anything against Germany, Antic will in all likelihood be forced to reshuffle his set up.

With Lukovic suspended, Antic should field Neven Subotic alongside Nemanja Vidic in the centre of defence and is also likely to introduce crafty winger Zoran Tosic, who can take on defenders and create space.

Danko Lazovic could replace either Zigic or Marko Pantelic up front and Kuzmanovic, who gave away the penalty, still looks a better choice in midfield than out-of-form Nenad Milijas.

Serbia also play Australia in its final group match in Nelspruit on June 23.

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