Soxprospects did say that - and it made sense given he was acquired to convert to catcher. That said, these places (and baseball america, espn etc) all thought he could stay behind the plate. Had good stolen base numbers and is a good athlete. (most of the guys who have to leave the positions are not) It's more likely a young Mauer-like athlete can figure out the stuff at the plate than a DH in waiting. I think at this point giving him some time to be comfortable is all you can do - and if that means doing so in Pawtucket, fine.
Right now the pitching staff is giving up more line drives than anybody, is in the top 5 for fly balls, dead last in ground ball rate. The Sox also have the 3rd highest homerun/FB rate. So right now this has been target practice for opponents, and Jason Varitek coming from the heavens to call fastball after fastball ain't going to fix that.