The Cottagers took the Moroccan international on a season-long loan in the summer, but he has only started three Premier League games and has scored just once, against Burton Albion in the Capital One Cup.
The 24-year-old fell out of favour with Redknapp over the summer, with the manager seemingly blaming the player's attitude.
"I just want good lads who go to bed early and get up in the morning, come to training, and earn their thousands of pounds per week," Redknapp told the Fulham Chronicle.
"I want those that think of other people who don't earn a fiftieth of what they earn.
"Adel's at Fulham. They're in trouble and Adel's not playing, and that must be disappointing.
"Maybe he's got to find himself another club. Whether we take him back or not is debatable.
"Would he get the message back here at QPR? He went to Fulham and I don't know if he got the message there."