If Bellinger opts in, then how about trade him to Colorado?
He'll hit in Colorado, the Rockies only have Doyle in center field, but will have Condon coming up in their system, so they need another outfielder. Blackmon will be 39 during the middle of next season. However, McMahon will be 30, Rodgers will be 29, Toglia will be 27, and Tovar will be 24.
I think Colorado can use another offensive bat and it fills a need at outfield/DH for the short term. If Bellinger performs well, then he can play himself out of Colorado by either trade or opt out.
The time for the Rockies to get going is now.