Japan coach Alberto Zaccheroni said Monday he has had no updates on Yuto Nagatomo's dislocated shoulder but is praying the injury to the Inter Milan defender is not serious.

Nagatomo has returned to Italy with the team doctor to undergo extensive tests after suffering the injury to his right shoulder in Inter's 2-0 win over Celtic in a friendly in Dublin on Saturday. The injury has ruled him out of this weekend's Italian Super Cup clash with AC Milan in Beijing and reports out of Italy suggest Nagatomo could be sidelined for up to two months.

That would be a blow to Inter's preparations for the new Serie A season and would also mean he would miss Japan's upcoming friendly against South Korea on Aug. 10 and possibly the start of the Blue Samurai's qualification campaign for the 2014 World Cup.

Speaking at Japan's training camp in Sapporo, Zaccheroni said, "I don't know the extent of the injury and haven't heard how long it might take him to recover. I'm just praying that it's not that bad."