The Black Cats’ club record £13.6million signing was selected in the Gabonese squad to meet Mali in a World Cup qualifier on Saturday.
And though the 22-year-old is understood to have been in Gabon’s capital, Libreville, since Monday, he did not report for training yesterday and has been sent back to Wearside.
The Gabonese Football Federation said in a statement that he was guilty of a “glaring absence”.
They added: “It was decided in agreement with the technical staff to inform the Sunderland the player is sent back to England from this Wednesday, November 9, 2016. His travel document had been amended accordingly.”