Fulham will be without attacker Bryan Ruiz for at least four more weeks after he suffered a setback in his recovery from a hamstring injury.
The Cottagers had expected to welcome back Ruiz - who suffered the injury in the 3-1 home defeat to Sunderland last month - against Newcastle on Monday.
But they now say the 27-year-old will not return to action until January, with manager Martin Jol explaining: "He came back on Monday, then he had a setback and he will be out for at least four weeks.
"It is the same injury. He was in the final stage of his rehabilitation and he aggravated his hamstring muscle again. He has had intensive screening and that highlighted some problems."
Costa Rica international Ruiz will undergo further treatment, and Jol said: "He had this hamstring injury before, and now we've found out it is a structural thing.
"We had a second opinion and hopefully we have found a solution now, but he needs treatment and he will be out for the next four weeks.
"Hopefully he will be fine in four weeks, but of course it is a big disappointment."
Ruiz, who took time to settle in at Craven Cottage, had been a key player in Fulham's strong start to the season.
"Bryan was a vital player for us and every time he played, like against Arsenal, Southampton and Wigan, he was quite important, but we've got other players," Jol said. "Good luck to him, and he will be back after Christmas."