The former Nigeria captain was reported to have been down with flu before the first leg African Nations Championship qualifying clash with Burkina Faso in Port Harcourt last week.
Oliseh reportedly broke down and asked to be taken abroad for treatment on Thursday.
Sources close to the Super Eagles camp said that palpable fear gripped the camp on Thursday and team and external doctors managed to stabilize his condition before he was taken to Port Harcourt airport en route Belgium.
"His condition has detoririated so much that he had to be flown back to his home in Belgium where he will be attended to by his personal physician. I have never seen him in this state before. It is very bad,"
It was gathered further that the Nigeria Football Federation have been briefed about the development, and have okayed his being flown to Belgium for treatment.
With this development, Oliseh will miss the second leg of the CHAN qualifier against Burkina Faso on Sunday.
