Well, this whole discussion was based on "when Rasmus returns", I am quite fine with Gose being here until Rasmus is better...
Rajai was more useful because he was a RH bat (and actually was really, really good against lefties...) so he could give guys like Rasmus and Lind breaks. With Gose being left handed, he doesn't really have a bat to displace in the line-up. Bautista isn't going to sit very often, Melky is a switch hitter and Rasmus is a lefty, so there just aren't any ABs for him when everyone is healthy on this roster.
Pinch runners aren't used particularly often, and late inning defensive replacements are, by their very nature, 1-2 innings, 3 MAX. I'd rather he got regular playing time at AAA than incredibly sporadic playing time @ the MLB level. (I don't believe it would stunt his growth...)