Is it a slump if he's been in it for the entire season?
j/k, honestly with what he has been able to contribute the past couple of seasons, I'm ok for giving a guy a pass for ONE off year. But short of using him as a dh I can't really see the advantage of keeping him around, especially if there is a chance he could be traded to address a need as the sox get ready for that stretch run for the division title. The sole upside to his game is his bat, which makes up for the rest of his mediocre to sub-mediocre defense & speed.
I'm not trying to hate on the guy, but you gotta call a spade a spade here. Since he wasn't dealt before the deadline, if there is room on roster, then yeah, keep him (better him than K-Horn), you never know if the situation arises when you need him in the lineup, but don't try to justify we should keep him b/c we need another cheerleader/media whore you has never seen a mic didn't have a quote for. Sometimes those things have a way of backfiring...just like the whole shots of alcohol fiasco prior to each game he let slip last year.
As far as Renteria goes, I for one would have probably preferred to keep Cabrera after what he was able to give us after the trade last year and I thought he was pretty clutch in the playoffs. Despite his career numbers, I wasn't impressed w/Renteria. I mean c'mon, its not like St. Louis went out of its way to keep him, especially for what he was asking. If you ask me, St. Louis is better off with Eckstein than with Renteria (and I'm pretty sure for less money.).