That is the scenario that would open up a can of worms. If Swihart is tearing up ST'ing and/or AAA, but has shown little progress on defense, how do we justify keeping him at catcher in AAA for too much longer?
There's LF vs LHPs (assuming we might think of platooning Beni/JBJ).
There's 1B, if they want to teach him yet another position before exhausting the catcher chance.
There's DH, which is not ideal for an athlete like Swihart, but for one season or part of a season, sometime you have to do what is best for the line-up, and to hell with the growth model set up for Swi to become a capable catcher.
If Leon or Vaz are struggling, calling him up would be easier, but both Vaz and Leon are out of options. We'd have to be pretty sure Swi "is the man" to trade away Leon or Vaz. I guess we could invent a DL excuse, but how long can that last?
I know Sox management is committed to giving him every chance at catcher, but thinks happen that change plans.