The young forward has impressed in preseason, creating issues for Brest in a 1-0 friendly win.
While he is seen as one for the future, Heckingbottom knows why Magpies assistant Jason Tindall is such a fan of the player.
"Will has got moments in him, which are really exciting, where you can't play him because he's got pace and power," he told ChronicleLive.
"If he squares the defender up, he can go the other way. Stepover left foot, stepover right foot and bang.
"That's probably why Newcastle have bought him because they can see that potential. Physically, he can get better and he's still a work in progress. He's nowhere near ready to lead the line from day one and play a lot of minutes for the club.
"That know-how is probably the only bit missing for Will at the minute, that game intelligence that allows you to contribute for 90 minutes, rather than just being on the pitch hoping you're going to produce that moment of magic.
"Listen, Newcastle know this. They're aware of it. They know where he needs to improve and they will be working with him. Sometimes, it's just time. They know they're buying a project and someone to work with."