Rafa did get a bit nervy himself at times in the last round. He's not as mentally string as he used to be... but Roger looked ashen when he came off court....
I'm also thinking we're overlooking Dimitrov. He's not an easy out for Rafa tomorrow and no gimme for Roger either if he makes the final. He hasn't lost a match this year.
I worry about Rafa's nerves tomorrow, more so than if he were to face Roger in the final. I think at some point in the final he'll relax (he tends to do that against Federer) because he has an easy blueprint to follow and he can always rely on drawing errors from Roger. But I worry about the sudden tightness he seems to have every match when he plays Grigor
I don't think Dimitrov has turned a corner in his career or anything, but that doesn't even matter. Right now, he's playing like he did and he's super confident.