The Leeds head coach has been discussing his injured players.
Leeds lost 2-1 to Brighton thanks to a late Bobby Zamora winner and had to endure the entire game without star man Taylor.
The 22-year-old had been an ever present for United this season but a viral infection meant he had to sit this one out - while Rosler believes he will also miss the Fulham game.
Meanwhile, centre-back Liam Cooper was also forced off during the 2-1 loss and the German admits that injury does not look good, either.
Rosler told LUTV: "Charlie Taylor has a viral infection. I don't think he'll make the Fulham game.
"I have not spoken to Liam or my medical staff but, the way he limped off, I don't think that looks good."
Leeds are three points off the Championship relegation zone after yet another home defeat.
There is no luck for the Yorkshire side right now, while they aren't doing enough to force their own luck, either.
Brighton performed poorly at Elland Road but are, at the end of the day, the league leaders, meaning Leeds wouldn't necessarily have expected points here.
In the coming weeks, though, the points need to come from somewhere. What must Rosler do to put things right?