The Buenos Aires sports daily Ole said in an editorial on Wednesday the time is ripe for key midfielder Juan Sebastian Veron to assume the captaincy of the World Cup favourites.

But unless coach Marcelo Bielsa heeds their call, Ayala will lead Argentina from the back in their group F opener against Nigeria in Ibaraki on Sunday.

"We haven't talked about the subject of the captain. The coach decides whether we change (captain)," Ayala said at their training camp on Japan's Pacific coast north of Tokyo.

"I'm not bothered. What I lose sleep about is playing and winning the World Cup, not whether I'm going to be the one to lift (the trophy)," the 29-year-old veteran of France '98 said.

Midfielder Javier Zanetti was captain in Argentina's last World Cup warm-up match against Germany in the absence of Ayala and Veron, with the latter leading the team in Argentina's other two international friendlies this year, which Ayala also missed.

But Ayala, captain for most of Argentina's 18 World Cup qualifying matches, wore the armband in both their practice games against J-League opposition at their J-Village camp.

Argentina won 5-1 against Kashima Antlers last week, but were worryingly held 0-0 in a 50-minute game with FC Tokyo on Tuesday.

POOR PRACTICE

"It annoys you when things go badly in a training session, but you've got to take positive things from it. Bielsa always tries to put us in difficulty, so we resolve things when we're drowning," said Ayala.

"You have to know how to play when you've been booked," he added, having been shown a yellow card against Tokyo.

Ayala said winning the Spanish league title with Valencia helped boost his confidence for the Korea/Japan tournament.

"But there are also people here who lost (club competitions) and I see them equally motivated," he said.

He was thinking of the likes of Manchester United's Veron, Zanetti of Inter Milan and Diego Placente of Bayer Leverkusen, whose clubs narrowly missed out on domestic and European honours.

Looking ahead to their first group match against Nigeria, Ayala recalled having faced lanky Arsenal striker Nwankwo Kanu playing against Valencia in the Champions League.

"He's difficult to play against, skilful despite his height, good with his feet, you don't know which way he's going to go," he said. "But we've go no specific plans for individual players."

After playing Nigeria, Argentina face England and Sweden in group F of the finals being co-hosted by South Korea and Japan.