Shinji Kagawa has been ruled out of Japan's friendly encounter against Brazil on Tuesday.
The playmaker, who rejoined Borussia Dortmund from Manchester United in August, suffered a head injury during Friday's 1-0 win over Jamaica.
He played the entire 90 minutes, but the 25-year-old later complained of dizziness and was taken to hospital for tests, where he was diagnosed with concussion.
As a result, he will not travel to Singapore with his Japanese teammates for the clash against the five-time world champions and will instead return to his club.
