Margetson has sent a video to the FAW that he hopes will prove he made no contact with Julian Joachim and that his red card should be rescinded. A verdict is due next week.
Margetson's dismissal, the first in his career, means a 1 match ban if the appeal fails. That game would be against Reading on March 16th.
Margetson, 32, is also hoping for a new contract offer from City.