Bear in mind that with the short turnaround of games, it's likely players will be rested if there are others who play in their position and are fit. I assume that's why Royston didn't play last week, and if Ainscough does miss out today, that is what I would expect the reasoning to be, since Ah Van & Raynor are fit.
I wouldn't see this as a reflection of his performances. Not unless Mick has been watching a different Shaun Ainscough to me anyway! He will no doubt be disappointed missing out on this game, but I would hope it's rested rather than dropped.