I don't see any incentive for the Twins to sell players with multiple years of team control remaining. They're not having a good season, but they have the talent to make the playoffs as a wild-card team next season.
I will make an exception to that for Justin Topa and Brock Stewart. Both relievers are on the wrong side of 30 with a long history of injuries. I would try to sell both of those pitchers at the deadline. They're paid almost nothing, currently effective and healthy. They each have quite a bit of team control remaining but I'm pessimistic they will be able to pitch effectively for those remaining seasons.
I would sell on Paddack, Castro, France, Bader, Coulombe, Vazquez, Stewart and Topa. That's a lot of roster turnover but it leaves the best part of the pitching staff intact.