The 19-year-old striker spent two months on loan at Victoria Park from Sunderland last season. His nine-game stint convinced Cooper that with another loan or two to learn his trade, he can cut it with the Black Cats.
"He can be a Premier League player," Cooper told the Sunday Sun.
"Whether it will be now, I'm not so sure.
"But if he gains experience whether it's here or elsewhere, he can do that.
"He's very hard on himself. I said to him he can't be as hard on himself."