The Sept/Oct roll which lists this man as present confirms that he was present and available for duty at the end of that period. He could have missed the Battle of Chickamauga GA (Sept 19-20, 1863) and reported for duty as late as Oct 31st. In fact if the roll was composed later than Oct 31st (and that happened as often as not), he might have appeared in camp even later.

An officer or an enlisted man who returned from furlough but still needed medical attention could be reported on roll as 'present, sick.' That's unusual but would mean that a man was present in camp but unable to perform basic duties. At the end of a furlough a man such as you describe would've reported at the nearest military hospital for examination. Doctors would have either kept him for treatment or sent him home with a furlough extension. If well enough to resume duties, he would have been sent on to his regiment.