He won't be sat for D'Arnaud, by the time TDA is healthy they'll probably be able to flip Buck for something at the deadline, although Sandy doesn't seem to like to do 'B' deals (i.e. not dealing Hairston or a couple other guys last year). But yeah if D'Arnaud was healthy it'd be an interesting quandry in the meantime.
I was saying if D'Arnaud was healthy and playing well enough in AAA to warrant a call-up. Once D'Arnaud got hurt, that question was rendered moot.
Not sure how much the Mets could get back for Buck...a mid-tier prospect and maybe a low-level "maybe" type. Could get more interesting if a contender loses a catcher to injury.