Jack Flaherty was a pity signing for the Tigers and it paid off well for them.
Nobody wanted that guy last winter. Somehow he put together a really strong season and now he's one of the premier trade chips this summer.
The Yankees are wise to kick the tires on him. And the Tigers should be asking for a lot because they need all the prospects they can get.
That said, looking at this as a Yankees fan, I wouldn't give up someone like Jasson Dominguez or Spencer Jones. Chase Hampton is hurt so he's off the table.
I would imagine Detroit is looking at someone younger to fit their timeline, because they aren't going to be very good now. So maybe shortstops George Lombard Jr or Roderick Arias. Pitcher Henry Lalane, outfielder Brandon Mayea, outfielder Francisco Vilorio. I can't say that I'm familiar with these guys but scrolling through their top prospects, those are the guys in their teens that would make sense in my mind.
That said, if Detroit does move Flaherty for very young prospects, that indeed signals that their winning timeline is 4-5 years in the future, and therefore would put me on notice that Tarik Skubal will be moved relatively soon also -- because there's no reason to hang onto him when he'd be 32 or whatever when the talent around him catches up.