Feyenoord midfielder Shinji Ono has given Japan coach Zico a few more gray hairs after becoming the latest key player to join the casualty list, just 48 hours before Japan's vital World Cup qualifier against Bahrain on Friday.

Ono hobbled off the pitch midway through a training session match in Manama on Wednesday after apparently hurting his toe and was whisked off to a hospital for tests.

His Dutch club later said the playmaker has broken a bone in his right foot, serving yet another hammer blow to Zico, who is facing the heat after a series of inept performances by the team.

The injury means Ono will also miss Japan's next World Cup qualifier away to North Korea in Bangkok next Wednesday, and Feyenoord officials said he is doubtful for the Confederations Cup in Germany kicking off the following week.