The 20-year old winger is making a big impression with the Glasgow giants, marked by his match-saving performance in the 3-3 draw with Kilmarnock last week, and Levein feels he will be a future Scotland star along with Liverpool’s Danny Wilson and Blackburn Rovers’ Grant Hanley.
"James is still young so we're dealing with potential,” he said.
"But I have to be clear in my mind that a player has the qualities to be an international footballer.
"And although it's just potential, he's in my squad because I firmly believe - with my experience - that James will play international football.
"I'm not wasting my time bringing someone in who I'm not sure about. It's the same with the other boys I have, Danny Wilson and Grant Hanley.
"And I expect that in the future for Scotland. Hanley and Wilson will also do it at Blackburn and Liverpool.
"He's just happy to play and he does it with verve. Young players don't understand pressure at that age. What sets him apart? "His decision making, simple. His decision making is good and if you see a young boy making the right decision more often than not, it's a great indicator of how he'll progress.
"Sometimes I watch young players and they're so erratic. They'll show something international class then the next minute they'll do something from the school playground.
"But Forrest, Hanley and Wilson make the right decisions at such an early age."