Japan coach Alberto Zaccheroni said his team had played at just 50 percent of its capability during a 0-3 loss to Brazil here in the opening match of the Confederations Cup.
The 60-year-old Italian vowed the Blue Samurai would improve for their next fixture against Italy at Arena Pernambuco in Brazil's north-eastern city of Recife Wednesday, reports Xinhua.
"I think that today we haven't shown what we are capable of. We were only at about 50 percent of our potential," Zaccheroni said after the match at Mane Garrincha Stadium Saturday.
Zaccheroni also praised Luiz Felipe Scolari's team saying the host nation had been spurred by the support of 70,000 mostly Brazilian fans.
"We have to give credit to Brazil's great performance. They played with emotion and the confidence that goes with playing at home in the first match of the tournament."
Japan guaranteed their place at the World Cup next year with a 1-1 draw against Australia earlier this month.
