You are right, Miranda did play a ton all spring—through an injury no less.
It’s a case of ‘Load management for me, none for thee’
So you have Buxton, who they are giving a ton of rest to, managing his load, in order to keep him healthy and at his peak performance for the long season.
Meanwhile, you have Miranda, who played all spring as you said, and has appeared in every regular season game and almost always in the field for all nine innings. What about load managing for Miranda so his performance doesn’t suffer?