Sunderland fear losing Papy Djilobodji and Lamine Kone to the African Cup of Nations.
The Daily Mail says Djilobodji has not played for Senegal for nearly two years and was not part of the squad which qualified for next month's finals in Gabon.
However, there is talk of the 28-year-old being recalled on the back of his performances for Sunderland in recent weeks.
Former Portsmouth midfielder Aliou Cisse is in charge of Senegal and, should he call upon Djilobodji, Sunderland will be powerless to prevent him representing his country.
It would be a blow for Moyes, who is resigned to losing Ivory Coast defender Kone for up to four weeks in the New Year.