El Khayati joined QPR from Burton Albion in the January transfer window, but he has been unable to break into the London side's starting line-up on a regular basis so far.
The attacker has made just two starts for Rangers to date, but he made a great impact after coming off the substitutes’ bench in their most recent outing.
El Khayati scored the winner off the bench in QPR’s 2-1 victory over Charlton Athletic yesterday.
And Hasselbaink said: “He has great potential – and is different to what we have here.
“He can go left, he can go right. He loves getting the ball in tight spaces.“
"It was a finish of real quality, and he showed what an asset he can be for us.
“I’m really pleased for him, because he’s been desperate to play.”
QPR’s win over Charlton was a hard fought one, as they were not at their best throughout the contest.
The R’s have been in good form of late, but they had to show their battling qualities to beat the Addicks.
QPR have now won four of their last five homes games, with the optimism levels rising at Loftus Road ahead of next season.
Rangers are currently in 11th place in the Championship table, with their next match coming against Cardiff City.