In response to moonslav59's comment:
I think we have the players in the system to replace Salty, Napoli, Drew and the pitching vacancies. And at a low cost.
While I agree that Bogaerts/Middlebrooks at 3B and Iggy at SS looks pretty nice compared to S Drew at SS and Iggy at 3B, I'm not sold on D Ross/Lava/Vazquez at catcher for 2014 or Carp/Middlebrooks at 1B. We also will need a significant pen build up and, to me, a big starting pitcher.
I'm really not sure why so many psoters seem to be more comfortable with Lava, Vazquez, Middlebrooks, Alex Wilson, de la Torre than Jackie Bradley Jr., Brentz or other OF in-house options. They are "low cost" too.
I don't know about Brentz, but I would be comfortable with Bradley. I think he is ready. He would not necessarily have to replace Ellsbury. Nava moving to first base is one possibility. Especially if Middlebrooks does not work out. I think Iglesias at short and Bogaerts at third is close to a certainty. If we think enough of our pitching prospects that we are reluctant to trade them , then we should have faith in promoting them.