The Black Cats will lose four players to the African Cup of Nations in the New Year.
Moyes admits it will mean another busy transfer window in January.
“We knew about the African Nations and if I'm being honest, it's not the way I would have wanted it but that's the way it's come around," he said.
“We brought in Jason Denayer so we have another centre half but will need to look to add again whether through the loan market or permanent.
“At the moment, Papy is not in the Senegal squad so maybe we might not lose him."