Sorry don't know your full story but can you let him just roam round your room? I have always let mine have free run of the room in the evenings, my first hamster in my uni room and my current hamster in my living room. As long as there are no holes in the wall (pipes etc) its fine, they might disappear under furniture at times but in my experience they always come out again
They really enjoy exploring the room and its nicer than being trapped in a ball, especially if you can arrange it so they can get in and out of the cage when they want.