Can you backup to a Time Machine sparse bundle over USB

Right now I have Time Machine backing up to a Network volume (external hard drive connected to my modem), but right now my ethernet cable is broken and it backs up way to slow over wifi, so I would like to just hook it up via USB to my Mac, mount the backup volume, and continue backing up over USB. Is it possible to force Time Machine to do this?

Thanks for any help
Alec