Positions in RUSH

So many times this game has put me on defense, even though I play as a striker and my team has a midfielder, sometimes a defensive midfielder, sometimes even a center back. So why does the game put me, a striker, on defense? Even after I've scored a goal or provided an assist, when I'm in the middle of an attack near the opponent's goal when the goal is scored, and when I'm away from my own goal when the goal is conceded? When people programmed this mode, what were they thinking?