I'm not saying this is right, but I saw it put this way.
If you are going to bring back JD on a QO at $18M, he's probably playing 1st or DH'ing with Vlad getting most of the reps at 3rd. To have that spot, you may be eating Morales's $11M contract (releasing him or moving him with $$ for nothing). That means you may be paying $29M for the change that JD bounces back and you can get some prospects for him on an expiring contract.
Considering what teams got for expiring deals this year (which was next to nothing) and that Moose just got $6.5M on a 1 year deal this offseason as a FA. That's a hefty price to pay.