Japan has been given a timely boost after one of coach Alberto Zaccheroni's most trusted players on Saturday declared himself fit to play in Tuesday's crunch World Cup qualifier away to Jordan.

Laid low with a fever earlier this week, Gamba Osaka utility man Yasuyuki Konno returned to train with the team on Saturday after sitting out Friday's 2-1 warmup win over Canada in Doha.

"I feel in really good condition and I am confident I can play," Konno said after a light 90-minute workout of stretching, running and ball work at Khalifa International Stadium.