The question always is: What (who) gives us a better chance of winning? Staff must decide that, obviously, but that is the yardstick they use to make the decision.
And it isn't just a matter of Blade pitching well. To bump Dolly, he would have to pitch very well AND give us 6 innings at least, because that's what a healthy Dolly gives us almost every time out, or more. I'm usually one to think that a starting player should get their position back after returning from injury, but that always presumes the second stringer is less of a player. Not necessarily true here. And that's saying something, as good as Blade and Dolly are.
I also think it might actually be a moot point: With Dolly's injury and Burns 'struggles' (relative term), we have the necessary indications to show us that we will need all four of these pitchers down the stretch. I'm guessing they all get plenty of innings one way or another.