If Tulo and Martin are traded, the value the Jays receive back will be pretty minor, if anything at all. Martin is unmovable with his contract, and Tulo is still a good player but not what he used to be (plus he has a ntc). At this rate the team might be better off keeping them even if they do rebuild since there is no SS or catcher ready to take over for them, and some vetrin leaders around a young team might help in development.
The players the jays would have to move are Donaldson, Estrada, Liriano, Happ...and if you want to include young guys, then Pillar and Osuna as well. That's where there will be value coming back to varying degrees. I doubt they will move Sanchez and Stroman yet unless they want to completely bottom out.