If he will come back to Miami in a backup role to Crowder, why not bring him back for 1 year or two.
They couldn't ask for a better guy to put the communications helmet on than Zach.
The perfect scenario would be to draft Scott Mckillop and let him learn from Zach and Crowder for a year or two and then beat Crowder out later.
I for one simply would like to thank Zach, for all he has done. I named my son after him, and whatever he chooses, I shall forever respect him as a player, an idol, and one of the greatest Iconic figures to grace the field.