Sessegnon was sent off 20 minutes from the end of the 6-1 defeat at Villa Park following a challenge on Yacouba Sylla.
Di Canio insisted there was no malice on the Benin forward's part and confirmed the club will ask the Football Association to take another look at the decision.
A three-match ban would rule Sessegnon out for the remainder of the campaign and the Italian said: "There was not a straight leg.it is not a bad challenge.
"I think once the referee has seen the clip he's going to realise the dynamic of the challenge can put him in difficulty.
"In reality, when you see the clip there isn't any intention to damage the opponent. The leg was not raised. We're going to appeal, of course."