One of the things I love about football, is how the sport allows so many different types of physiques to reach top level. Just look at the massive difference between Ronaldo and Messi! Being a skinny guy, it was always inspiring to see people with my physique make it(even though they obviously had better stamina and lower body-fat percentages).
Because of this, I never really had a problem with Rooney and his physique. As long as he performed well, I couldn't be arsed if he looked a bit heavy. The thing is; Rooney at his best was an explosive and assertive player with a knack for scoring goals. Take away these qualities, and you're left with a fairly mediocre player(by United standards). He's been sub-par for 2 years(and he wasn't THAT great under Moyes either), and given his age and the fact that he's already played more top football than most top professionals in their mid-thirties, it doesn't look good for him. He's just not smart and silky enough to be a CM. He's not explosive enough to be a no.10 or a striker. He's done, I'm afraid.