Grayson takes his side to Leyton Orient on Saturday looking to keep up the pressure on leaders Norwich.
"We have to take a lot of positives from how we played on Tuesday," Grayson told the club's official website. "We went a goal down and got back into it and we kept going and going.
"There's a lot of character and desire in this club. We've shown all season a desire and inner strength and it will bode well for the season, I'm sure.
"Our sole focus is on getting this football club back in the Championship and I'm very confident we can do that."