Morelos was sent off early in the season opener away to Aberdeen, which ended in a 1-1 draw after a dramatic late equaliser from the home team.
The Colombian was dismissed after 12 minutes for kicking out at Scott McKenna, although it took intervention from the assistant referees to spot it.
"I had a good conversation with Alfredo," Gerrard said. "The chats that I have with my players will always stay private.
"The card has been rescinded, which we are very happy about.
"But that doesn't take away from the fact that we believe we've dropped two points because of that decision.
"We totally understand how difficult it is to referee these big games and our respect is certainly there. It's just disappointing for us that we're on the receiving end this time round."