i reckon there's not a bad song in here screaming to get out - i heard it as a simple acoustic thing to begin with but the temptation to tamper is overpowering sometimes, so now it's almost rock.
a wantaway player, by the way, is usually a footballer who wants to leave his club and earn even bigger money elsewhere. i don't play football, so for me i guess it's a metaphor for something. ;-)