New blood and a change of formation paid dividends for France as debutant Mathieu Valbuena netted the winner in a 2-1 World Cup warm-up win over Costa Rica on Wednesday.

With 16 days until the start of the tournament in South Africa, the Netherlands also secured a morale-boosting win as Robin van Persie scored twice in a 2-1 victory over Mexico.

France, playing in a 4-3-3 formation instead of the usual 4-2-3-1 under coach Raymond Domenech, produced some neat football but looked shaky at the back.

Midfielder Carlos Hernandez put Costa Rica ahead early but an own goal restored parity and Valbuena struck seven minutes from time.

The Dutch, without a number of regular starters including Arjen Robben, Mark van Bommel and Wesley Sneijder, followed England's example by overcoming Mexico.

Van Persie proved his worth as central striker with two fine volleys to give Mexico coach Javier Aguirre some thinking to do after another inconsistent performance, following their 3-1 defeat by England at Wembley. Javier Hernandez headed a consolation for the Mexicans 16 minutes from time.

"Van Persie was excellent tonight with two beautiful goals, but we missed the power in the second half and allowed Mexico to play much better," Netherlands Bert van Marwijk said.

Australia became the first team to arrive for the World Cup when they landed in Johannesburg.

"For everybody, this is a new experience to train and to play in altitude," coach Pim Verbeek said at Johannesburg's OR Tambo airport.

"So we have to find out how it works and what we can do the upcoming days, we still have work to do, but that's why we have 15, 16 days to prepare ourselves."

If the World Cup suddenly seemed a lot closer for the Australians, Spain midfielder Cesc

Fabregas was still being forced to duck questions about his club future.

Fabregas, a transfer target for Barcelona, had hoped to get his future sorted out well before the start of the tournament but the Arsenal man had to leave his fate in the hands of club manager Arsene Wenger.

"He told me to concentrate on my football and to concentrate on the World Cup," Fabregas told reporters at Spain's training camp in Madrid.

"He told me to leave it in his hands and he will deal with whatever happens with my future. That's what I'm doing. Just concentrating on football."

If economists are correct, Fabregas and his national team-mates will be concentrating on football right up to the final on July 11, with a poll released on Wednesday tipping them as winners.

Reuters polled a global field of 74 soccer fan economists and 24 respondents said Spain would follow up their Euro 2008 success with triumph in South Africa.

A total of 23 expected Brazil to make it six World Cups, while just one economist expected Italy to retain their title.

There are more serious calculations to be done by coaches, of course, with the June 1 deadline for naming their final 23-man squads looming.

United States coach Bob Bradley named his party on Wednesday, keeping faith with central defender Oguchi Onyewu.

Experienced striker Brian Ching was the surprise ommission from the US squad.

Germany coach Joachim Loew has named his final squad. It has already been reduced to 22 by an injury to midfielder Christian Traesch and the coach will be relieved it was not reduced still further.

Striker Thomas Mueller crashed during a mountain bike run with squad members at their Italian pre-World Cup training camp, needing several stitches to his injured chin, but avoided any bone or muscle injuries.

The opening match at the World Cup will be played at Soccer City, where South African tribal chiefs and healers have slaughtered a cow outside the stadium as part of rituals to appease the spirits of ancestors and welcome fans.