The 22-year-old had been in talks with Paris Saint-Germain over a possible move to the French Ligue One side but any move for the Moroccan appears to have fallen through.
Warnock believes that if the Championship player of last season were to move, he would head to a club outside of England.
"It would be disappointing to see him go, but far easier for a manager to deal with," the QPR boss said.
"This is the only club for him in England. It's whether anyone comes in for him from abroad that's prepared to buy him.
"It's unlikely that clubs will want him because he's not proved himself in the Premier League. He's a top Championship player with a lot of ability."
Taarabt scored 19 goals in 44 appearances for QPR on their way to winning the Championship last season.