Everyone goes crazy saying he should play up front because they're his mates (see the Neville brothers - especially disappointed in Gary as he used to not take any prisoners in his punditry) Rooney shouldn't play upfront because Martial is better. He shouldn't play as a No 10 because the criminally underused Ander Herrera is miles better, as is Juan Mata. He shouldn't play deeper in midfield because Schweinsteiger, Schneiderlin and Carrick are all better. And Fellaini is probably better in all of those roles than Our Wayne too.
It's not even that Rooney is not as good as these players, he is actively damaging United. Against City, he completed nine passes in the first half, and gave the ball away seven times. No shots on target. No chances created. A passing accuracy of 55% (the lowest on the pitch). Lost possession 28 times (highest on the pitch). One touch in the opposition penalty area.
I don't understand why people are clamouring to say "No no, he's not finished!" There's no shame in the performance of players slowly decreasing as they get older. "But he's only 30 he's got 5 more years left!" It's not an exact science where players are fine up until, say, 33 and then as soon as they blow out the candles become beyond redemption. With Rooney you have to remember he was a very early physical developer, breaking onto the scene at 16 and he's played a lot more football than other players his age - that kind of thing really takes its toll. It's not surprising or shameful that he's peaked a couple of years before the traditional age of footballers. See Michael Owen and (Brazilian) Ronaldo for other examples of that.