The Scotland international, 21, was dismissed after just half an hour for sticking his arm in the face of Wigan's Nick Powell and will serve a three-match suspension.
"Grant has been in to see me to apologise to the staff, his team-mates and to the fans for his actions," manager Gary Bowyer told the club's official website.
"He was absolutely distraught after the game as he felt he had let everyone down.
"He has enjoyed a fantastic rapport with the supporters since breaking into the first team three years ago and he doesn't want that relationship to be tarnished.
"He has held his hands up, accepted his punishment and will be cheering the lads on from the sidelines at the next three games."