How do i backspace one character in Google Assistant

[caltroon]

When I use the microphone for messaging in assistant I can't figure out how to backspace only one character. If I press the X in the little arrow box next to the microphone symbol during a message it deletes the entire word. I have to get out of microphone by pressing the back arrow next to Tap to speak to go back to the keyboard to delete one character. Is there a way of deleting only one character in a word while in assistant rather than the whole word? I have Android 6.0 and the newest Google Assistant.