If we assume Bolsinger and Biagini are both in the bullpen (and maybe Sparkman) - then the only other depth we're going to add are guys like Oberholtzer or some old vets trying hang on who we can stick in AAA (like we did in the past with Randy Wolf, Carmona, LeBlanc, etc.). We don't really have any good prospects who are on the verge of contributing.
I think we'd all like to see some more depth, but unless we're trading for a SP prospect on the verge of helping the big league club - it seems highly unlikely to happen.