Didier Ndong has apologised and explained the reasons for his no-show which saw Gabon send him home from international duty.
The Black Cats’ club record £13.6million signing was selected in the Gabonese squad to meet Mali in a World Cup qualifier last Saturday.
The 22-year-old had travelled to Gabon’s capital, Libreville, but did not report for training and was sent back to Wearside.
The Gabonese Football Federation said in a statement that he was guilty of a "glaring absence".
But Ndong has now explained his absence in an interview with Gabonese newspaper l’Union, with the midfielder revealing he had not turned up to training because his wife had recently given birth.
Ndong said: "When I arrived, I dropped my stuff in my room [in the team hotel].
"Then I went to my home, like many of my team-mates.
"Before, I informed the staff that my wife had just given birth and I let myself be carried away by this euphoria.
"These are the reasons for my absence from training on Tuesday."
Ndong denied claims from the Gabonese Football Federation that he was uncontactable.
An apologetic Ndong added: "That is incorrect.
"I use my foreign number when I am in Gabon but there are network disruptions from time to time.
"When I was left out of the group, my uncle and friends called me by that phone.
"I love my country more than anything.
"I wish to apologise to the people of Gabon, to those who believe in me and who do not cease to support me.
"Being sent home hurts me but I’m always available for my country."