Default Softbrick push file to SD card

My N7 is softbricked. I've been unable to flash it back to stock. I've tried several ways and recovery files and none of them work. Is it at all possible to push a zip file to the internal SD card while it's in the bootloader or something along those lines? Using the Nexus Root Toolkit I see that it is possible, however because it's softbricked it won't let me since I can't enable USB debugging and such.