Newcastle boss Alan Pardew says Papiss Cisse may be forced to miss Saturday's clash against Swansea due to a dispute with Senegal.
The striker withdrew from the national squad for Wednesday's friendly away to Niger with a back complaint, but Senegal are arguing that they never received a medical report on his condition.
The West African nation are now threatening to invoke FIFA's five-day rule, which entitles an FA to suspend a player who fails to turn up for international duty.
"We have a bit of an issue going on with the federation," said Pardew.
"We feel we have covered all the bases to give them the information.
"But they seem not to have received it, so we are in discussions with Senegal and the FA about his availability for Saturday."
Cisse scored 13 goals in 14 matches last season after joining from Freiburg in January, but has failed to hit top form so far this year, hitting the back of the net just once in 10 league games.
Nevertheless, with just one win in their last six Premier League matches, Newcastle will be keen to field a team which is as strong as possible.