One thing has always bothered me in FM.
When, following a set piece (free kick, corner or line-out), a player 'out of position' finds himself in a position that is not his, but with the ball at his feet and an excellent chance of making an important action, but instead remains stationary or even prefers to go back (typical of central defenders) and then pass the ball to the usual midfielder.
I understand that some players aren't great crossers, or don't have great finishing, but I prefer to see them soundly miss the shot / cross, than to see them come back.