Let me put it this way. The older grouping of guys like Stiever/Sheets/Lambert/Burger/Adolfo, etc are guys that are primed to be moved.
#1, they ALL have significant competition ahead of them
#2 in the cases of Burger and Sheets they don't have the ability to add other defensive positions, or the ability to move around the diamond to get into games more regularly.
#3 the Sox have a list of players they will have to add to the 40 man roster and a roster full of decisions to make that they don't want to lose in the rule 5 draft which will also force them to make moves.
#4, options are running out for a lot of these guys.
#5 the Sox are trading players in the next few weeks to add to the major league roster, and they seem to be making a concerted effort to bring in a lot more young upside talent to really build for when the core of players that we have in Chicago right now start to get expensive and potentially able to leave Chicago. I get the impression they are more interested in keeping the younger guys than the older ones.