If the guys he would be "interfering" with suck or aren't ready next year or the year after, then can we be pissed off?
EDIT: also, I think the logic here is flawed generally. I'm reminded of the Mitch Hedberg bit, "If you are flammable and have legs, you are not blocking a fire exit." Similarly, if Salty projects to be worth his salary in 2015 and 2016, it doesn't matter if he's "interfering" or blocking someone - either he's better, in which case the prospect can backup or play at AAA, or he's worse, in which case he's trade bait. Maybe Saltalamacchia doesn't project to be worth 3 years / $21 MM, but if he does, it doesn't make a lot of sense to hold off because you think someone who hasn't played above AA might be good later in the contract.