A glass screen at the back of digitizer!

The phone was not responding to touch so I tried to replace the old digitizer with a new one. However when i disassembled my phone I found that there was a a thin glass screen attached to the old digitizer. It cracked when I tried to remove it off the digitizer, however, the front panel of the digitizer remained intact. My new digitizer doesn't have a glass at the back( which i think would act like a spacer between the digitizer and the LCD). If I assemble by phone with this, it will leave a space between the touch and the LCD.

I am not sure whether my interpretation is correct. Therefore, i will appreciate if someone can explain it. Also, it is possible to buy that 'spacer' separately.