Morrow's career high for innings pitched in a year 179. I hope you're not hanging your hat on him for a full year in the rotation, because that would be beyond dumb.
As for how the team is constructed and what we have coming in the next year, I would rather let Morrow walk. Morrow going forward best case is a late-inning 'pen arm, or an unreliable SP.
I would rather the Jays offer Kenta "Raine" Maeda a 6 year 126 mil deal to be a rotation anchor going forward, not Brandon "I can't pitch even close to a full year" Morrow.