Morrison, who is on loan at Loftus Road from West Ham, scored another two fine goals in Saturday's 3-0 win over Yeovil.
The England Under-21 international has now found the net four times in his last three appearances to boost Rangers' promotion bid.
Onuoha said: "He's got an awful lot of potential.
"He's a good player now, but if he continues to be nurtured and does things in the right way then he is going to be something special for the country."
While Morrison was shooting down Yeovil, his parent club West Ham were being comprehensively beaten at Stoke.
The Hammers could, in theory, call Morrison back this week, once the initial 28 days of his loan spell is up.
The 21-year-old was arguably West Ham's best player during the first half of the season and many of their fans are baffled as to why QPR are reaping the benefits of his talent rather than them.
Assistant manager Kevin Bond hopes it will not come to that, though.
"What will be will be," said Bond.
"He's here, he's enjoying his football and he's figuring. He's done great for us."