I know the point you're making, but if we need to be playing Derby for Nani to show his true worth, then I'm not sure he's half the player some of the folks on here seem to think he is.
My own tuppence worth, is that he's benefitted from being a mini-Ronaldo. He was bought from the same club, is a winger with two good feet, decent striker of a ball, and people assumed his development would go the same way.
It won't. He's potentially a very good player, but a far different one that Ronaldo. I honestly think if we'd never had Ronaldo at this club that Nani wouldn't have been afforded the sort of patience and understanding that he has been. I'm all for giving players, especially young players, lots of time, but he has to start repaying that soon. Because, at times, he's not even making the matchday squad, and he's potentially far too good for that.