With one year left for each of these guys, the trade returns aren't going to be that much better than the comp picks we'll end up getting for them. Is it really worth forgoing what could easily be another 90+ win season and WS opportunity? And after what Johnson and co. have pulled off the last couple of drafts, why wouldn't we want to give them those picks? If the season goes awry for whatever reason, you can always end up trading them at the deadline, too.
Offseason focus should be on extending Woodruff/Chourio and on getting Mark Canha/Josh Donaldson types to fill out the lineup alongside Yelich/Contreras and our younger players. Rhys Hoskins, anyone?