Arsenal's 18-year-old whizkid wins his 11th Welsh cap today when Scotland provide the opposition in Cardiff.
Toshack said: "There's never been any doubt about his potential. He has grown a little more in confidence, as you would expect.
"He's also shot up an inch or two. He is going to be an interesting one in the future.
"We've seen a big difference in him and we're expecting good things from him.
"When he plays more for Arsenal, the Welsh side will get the full benefit because there is no doubt about his talent."