Honestly, except maybe Casas, do the Sox really even have any untouchable prospects (without including the 2021 draftees)? And even Casas, while certainly a good prospect, shouldn't be untouchable in the right deal. He's a very one dimensional prospect. If he struggles to hit, what's left? Mitch Moreland without the defense?
I see people listing Noah Song and his 0 career IP above college as untouchable. He might be talented, but that designation is a bit much. His saving grace is he is probably out of sight/out of mind among a lot of baseball people.
I'm far from advocating selling the farm, but let's be a bit reasonable with who's available and who isn't...