Despairing of Japan's [Images] lack of killer instinct at the World Cup, the country's soccer chief said the missing ingredient was obvious: "We need a Kaka [Images]."

Japan failed to press their goal advantage and suffered a late collapse in a 3-1 defeat by Australia in their opening game on Monday, leaving the Asian champions facing an early exit.

"We keep on at the players to take more shots but they seem to lack confidence," said Japan Football Association (JFA) chief Saburo Kawabuchi.

The Japanese supremo added with a sigh: "If only we had a Kaka."

Kaka scored a superb winner for world champions Brazil [Images] in their opening Group F game against Croatia.

As several Japan players trudged off after training on Thursday with ice-packs wrapped around sore ankles and knees, playmaker Shunsuke Nakamura at least declared himself fit.

The midfielder dismissed fears he could miss Sunday's must-win game with Croatia because of a bruised thigh sustained against Australia.

NOT TRAINED

Nakamura has not trained properly since but said he would start at the weekend.

"I've been taking lots of hot baths and swimming to help soothe the injury," Nakamura told reporters. "It will be all right by tomorrow. It won't be a problem for the Croatia game."

Japan Zico is set to scrap the side's 3-5-2 formation in favour of a 4-4-2 with Nakamura on the left and Mitsuo Ogasawara coming in on the right of the midfield.

Nakamura looked relaxed a day after Celtic announced the 27-year-old had agreed a one-year extension to his contract that would keep him at the Scottish club until 2009.

"It keeps me there two or three more years -- I'm not sure how long," Nakamura joked. "It's a bit cold in Scotland but it's a big club with a lot of history.

"It was probably the fans who made me decide to stay. There is a lot of respect for the players which makes it different from Italy [Images] and other places. You can concentrate on the football."