I'm not a huge Tortuga fan, although he was fun to watch when he first came up, but I wonder who those who feel so strongly about him not being on the roster would like to see in the 26th man spot. They can only carry 13 pitchers so they need to carry at least 13 hitters. I can't imagine anybody is expecting them to sign someone who is taking regular ABs from Arraez. Can't imagine they want one of the young guys sitting on the bench and getting random ABs here and there and a pity start once every couple weeks. Can't imagine they want a guy who would take OF starts or ABs away from Rooker or Kirilloff. The 26th man needs to be a veteran guy who doesn't need to get regular ABs to continue their development (those guys need to be in the minors or part of the regular rotation), but can also step in in a pinch and not look like any of us on this site would look like trying to hit major league pitching. Willians isn't going to be an all-star. He isn't going to be a starter. But, as Nick explains quite well, he is uniquely suited to the 26th man spot.
Any scheduled rest for 3B, SS, 2B, and maybe LF comes with Arraez filling in. Any regular rest for OF comes with Cave filling in. Now maybe you folks want an upgrade on Cave as your 5th OF, but that has nothing to do with the 26th man spot. Then you have to have a catcher on the bench in case of injury so Jeffers or Garver are always on the bench, but are the fill in for the other for rest and you don't want your 26th man needing to take up any of their ABs. So that's 12 hitters on the roster. The 26th man should be someone who can mop up any extra ABs here and there for in game injuries and spot starts every couple weeks. Willians is uniquely qualified to fill that role.
If someone goes on the IL you call someone up to replace either Cave or Arraez in their roles. Or one of the catchers if they're the ones who get hurt. Willians doesn't suddenly start getting a ton of ABs, unless he's raking. But having Blankenhorn, Gordon, Kirilloff, Rooker, Celestino, or Rortvedt on the bench for 90% of the games and not getting ABs doesn't make sense. Can't imagine Marwan is ready to give up regular major league ABs to sit on the Twins bench if he can get them by signing elsewhere. In fact I can't imagine there are many guys drastically better than Willians who would be willing to play the 26th man role of limited ABs.
So throw some names out. Those of you who don't want him filling that role. Who do you want to be the 26th man? Have to assume you're looking at someone from outside the organization or not currently on the 40 man. So who would you have fill that role?