I wouldn't, even if it is for a month. If he has a ball right now, what is he keeping it in? There shouldn't be any reason why he can't keep it in it's current enclosure. You can never know if either snake has parasites, and if kept together, could spread it to the other snake. If one defecates, you don't know which one excreted it, especially if it looks abnormal. They will have to compete for hiding places, optimal temperatures and humidity, and in their minds, food. It will ultimately stress them out more than necessary. I would just keep them separate while he is living with you.