The 20-year-old is considered one of the best young talents in Switzerland, but he is yet to break into the club's first-team squad.
"Kasami is a youngster and if everyone is sound and well he won't start, he knows that," Jol told the Fulham Chronicle.
"That's a bit of a problem with him because he wants to play all the time. I feel he should do a bit better and push for a starting place but he's not there yet. I think he could benefit from a loan spell."
Kasami joined Fulham from Palmero in 2011.