I'm having difficulty getting this achievement.
By "open play", does this mean just the regular competitive mode against the computer? Does this need to be on a specific difficulty? I've tried heading the ball and that never seems to get it (jumping and not-jumping). I've also tried kicking the ball, and I've scored a few points that way but still no 'chivo.
I figure I must be missing something.
Best Answer
Try setting the difficulty to lowest. Everytime the ball comes to you put your hands behind your back and stick your head or foot out. Remember that the rallies follow the same suit. By this I mean, usually you stop the ball from hitting the ground (use foot here), it will then go to your teamate, who will throw the ball up for a spike (try heading here).
I found this much easier with an actual person playing as my teammate as the CPU likes to hang onto the ball sometimes.
Hope that helps and good luck!