The lone goal the Fire allowed FC Dallas in their 2-1 win Wednesday at Toyota Park came on a set piece.
That's become an area of concern for the Fire which is missing center back Arne Friedrich who is recovering from a strained hamstring.
With Friedrich out, the Fire has been vulnerable on set pieces and will look to improve moving forward.
"It's just being more diligent in our marks," Fire center back Austin Berry said. 'In the last couple of games it has not just been the first ball but it's been the second and third ball. It's staying in tune until the ball is clear and even when the ball is cleared still knowing where your mark is and being organized."