We will be ready for Argentina: Arnold

Olyroos coach Graham Arnold expects the adrenaline to kick in when his team takes on defending champions Argentina in their second group match on Sunday.

Australia drew 1-1 with Serbia in their first game of the Olympic soccer tournament at Shanghai Stadium, the same venue where Argentine star Lionel Messi led his side to a 2-1 victory over Ivory Coast.

"The adrenaline will kick in for sure when they go and play Argentina in a couple of days," Arnold said.

"Tomorrow will be about recovery and a light training session, and we're ready to go again - that's the beauty of this competition."

A well-taken goal by Australia's Ruben Zadkovich was cancelled out by Slobodan Rajkovic as the Olyroos became the first Australians in action at the Beijing Games, a day before the opening ceremony.

Australia should have had gone 2-0 up but substitute Billy Celeski's 74th-minute shot hit the post.

Arnold believed his players would pull up well, despite playing in very hot, humid conditions.

"It's the same for all teams and our players are as fit as they have been probably in their careers," he said.

"I probably will make a couple of changes because the players put a lot of energy and effort into tonight.

"We've got 18 players."

Messi scored Argentina's first goal shortly before half-time and set up the winner.

Two minutes into the second half, Sekou Cisse brought the Africans back into the game when he beat Pablo Zabaleta in the air to head home the equaliser.

But Lautaro Acosta was perfectly placed to score the decider when Messi's shot on goal five minutes from time was parried by Vincent Angban.

Messi took to the field immediately after Australia's match at the same venue despite his club, FC Barcelona, winning the right through the Court of Arbitration for Sport to stop him playing.

Barcelona, who wanted the 21-year-old for their early Champions League matches which clash with the Olympics, gave in at the last moment.

Socceroos coach Pim Verbeek can't wait to see the Olyroos take on defending champions Argentina, although he admits the task is huge.

"It will be tough for the Olyroos. We have to be honest about that," Dutchman Verbeek said in a teleconference from Shanghai.

"The players had a very good preparation, they are physically fit. Now they have to show it.

"It will be tough but I'm one hundred per cent sure that they will give everything to go through to the next round.

"I'm very interested to see how they play against a great team like Argentina.

"The most important thing for these players is to get international experience. They have got a lot of international experience in the past months and especially under difficult circumstances with climate like yesterday.

"I'm very pleased with all the games they have to play and the way they are growing as a player and also in their international experience.

"It was a tough game ... so I'm quite pleased with the result, with the way the players are acting."