At that point, I would rather let Arrieta/Hendricks/Grimm/Rusin/Cabrera/Villanueva battle it out. How many more offseasons are were going to go after a patchwork rotation? Letting those guys battle it out isn't going with a patchwork rotation? They all at least have a future in the organization and could probably perform similarly for a fraction of the cost. If Hughes were to sign cheaply, then I wouldn't be opposed. But I'd imagine we won't be the only team looking at him. To answer the original question, there will always be space for patchwork additions to the rotation. You need 5 guys just to field a team, 7 for much of the season and 8 or 9 in total over the course of a season, barring the rare 5 man 200 inning group. But those don't last even when they do happen. Also, I'm not sure why "all those guys at least have a future in the organization" but a signed Hughes would not. Villanueva is 2 years older. Arrieta is the same age. Any of those guys could be out of baseball in 2 years.