I'm a big fan of Delph, but I thought he was pretty poor Yesterday.
Like others have said, I think we need to see him playing in a more advanced role to see him perform better.
He is good at running at opposition players, without worrying about having only the defence behind him.
I'd like to see Gardner playing alongside Petrov/ Herd, and then have Delph further forward.
Though, we have a lot of players that play in a similar position... Ireland, Bannan, Delph, Gardner & Jenas can all play in an attacking midfield role.
If they can all get experience, we might have a nice set of players to rotate. But it's going to be a tough task to get them all the game time and experience that they'll need.