How many people in this room have played soccer before? If u have u would know that soccer require speed, endurance, and skills.
It may look easy, but if you don't have two of these, you are limited to play any position.
If you don't have speed, the opponent will fly bye you and score and you could not do anything because you don't have speed. For example, the ball comes to you and is slowing down and it is 15 yards from you. And you try to get the ball, but you cannot because the other player had more speed than you did. Now the ball is coming your way but you do not have enough time to decide what to do with it, you need quick reflexes to know what you're going to do with it. I remember watching a soccer game with two really good teams and the score ended up being zero-zero.
These two teams got up and down the field with so much speed; you could not even imagine it.
The thing every sport needs is endurance, but soccer needs it the most because you move around constantly. If your out tired and there is a player from the other team coming at you, you cannot say hold on let me catch my breath. The other player will just go bye you and score. The most important reason you need endurance is because you have to be able to stay at one speed for fifty yards with out stopping and do that for eighty minutes.
Most important this you need is skill and that is because you do not want to make a fool out of your self and not have any idea what your doing. You also want to have a distance and accuracy to who ever you're going to kick it to. It's a good idea to keep the ball away from the other person also and the only way your going to do that is with skill.
Overall, if your lacking in these two things you need to get better in all three of these: speed, endurance, and skill, but you can still play the sport soccer; but you will be limited to a position and will not have a chance to play any other location on the field.