The dude is 19 and coming off an ankle injury. He's been on the inactive list for games. He's probably stuck there unless someone is injured. He's caught in a bit of a numbers game. With healthier centers, Erden wouldn't be getting playing time and Harangody wouldn't be needed as an emergency PF, so a slot would theoretically be open for Bradley, if healthy.
He has a chance to play against Memphis because Jermaine O'Neal went back to Boston, Perk is out, and West is still suspended, so he will make the active roster, at least, and you'd like to think Boston can blow out the Grizzlies.