Blotchy area on new screen

My son dropped his iPod and broke the glass. I purchased a new screen with digitalizer attached, installed and closed it up. I then discovered the wifi antenna was broken. When opening again the layers of paper and such came separated from the glass. The new wifi antenna worked, and the screen still works. But now I have a greenish gray blotch right under the word iPod. The blotch seems to grow. I'm wondering if it is possible to fix this, or if I need purchase yet another screen and try again...