Someone else is probably better equipped to answer this, but without there being a Rule 5 draft last year, teams have basically two years worth of players that have to be protected on 40 man rosters, or risk losing them. Not sure if Carpenter is in that boat with us, but if he’s not, it may be a reason not to put call him up this season. Or, perhaps they want to maximize his trade value this offseason and fear he might get exposed against ML pitching.
Or, the front office is inept.