The fact the pain has subsided indicates it isn't a stress fracture....if he had a stress fracture the pain wouldn't have subsided so quickly.
Not necessarily. If it were a slight fracture, the pain could subside fairly quickly. But you still wouldn't want him playing on it as that could make it worse.
If memory serves, that's what happened to Kevin McHale. Had a stress fracture in his foot that he kept playing on because it was the playoffs and it just kept getting worse. He never completely recovered from it.