The Macedonian-born Switzerland Under-21 midfielder has become frustrated with life on the bench at Craven Cottage having only featured three times this season.
Kasami has reportedly been on the radar of two Italian clubs - Sampdoria and Lazio - while his former club Palermo have ruled out taking him back.
The 20-year-old has been tipped for a move to the Volkswagen Arena, although manager Martin Jol will only send him to Germany if he's promised regular games under head coach Dieter Hecking.
The Dutchman said: "Last time I thought it was better for him to stay here because I was not 100 per cent convinced he would play at another club.
"If you have players like Alex Smith, who go on loan and never play, what is the purpose?
"First there must be a club who will promise me to play them. Then we will think about it."