The 18-year old Burundi-born England youth international was in good form during the Baggies' pre-season tour of Sweden and Long is confident he can make an impact this term.
"He's a great prospect," Long told Express & Star.
"He's a good finisher - a natural goalscorer. He's working on other aspects of his game to bring him up to the right level.
"He's developing every minute and wants to learn and that can take you a long way in the game.
"He's still learning and is very young but he's a good prospect.
"Hopefully, he can kick on from here and make the most of being involved in a Premier League squad and make his position more concrete in the future."