Ki Sung-yueng blow for Newcastle
The midfielder, an influential player in recent weeks, has been called up for South Korea's Asian Cup campaign.
And Ki must link up with his international team-mates for a training camp next week ahead of the tournament, which is being staged in the United Arab Emirates.
United manager Rafa Benitez had hoped to keep Ki for some of the club's festive programme.
However, South Korea have rejected Newcastle's pleas, and the 29-year-old could be away until early February if his team reaches the final.
Benitez said: "Ki will play this game, hopefully, and then, after, he will go, because the manager wants him there on the 26th in Abu Dhabi for a training camp."
Asked if he had tried to keep Ki for longer, Benitez said: “Believe me, I was talking a lot about that, but there's no chance."
Ki spoke about the Asian Cup after last weekend's 1-0 win over Huddersfield Town at the John Smith's Stadium.
“It isn’t confirmed yet, but, by the FIFA rules, it’s two weeks before the first game, so it could be after next week," said Ki.
“I think they’re talking, there are negotiations, so it’s too many games I’ll be missing. It depends on the games. The final is on February 1, so it’s quite a long time.
“But I don’t want to be greedy, because we have good players. If I can’t play, I can’t play. Also, it’s crucial for my country. They haven’t won it for nearly 60 years. I can’t be in two places at once.”
Forward Yoshinori Muto has been called up by Japan for the Asian Cup, though he will be available for some of Newcaslte's festive programme.
Meanwhile, defender Federico Fernandez is back from injury for the Fulham game.
However, Ciaran Clark, Jonjo Shelvey and Karl Darlow will miss the game because of injuries.
“Shelvey, we still need to check how he's progressing," said Benitez. "He's doing well. We have lost Clark, who has a problem with his ankle after the game.
"Fede is fine and the rest of the players are fine.
“(Florian) Lejeune has been training, so to be fair, we have now Jonjo and Clark, and also Darlow, who still has a problem with his elbow."