The Scorpions were beaten 18-6 at Hemel Stags last week, but Grady felt that he saw some improvement.
“I asked the boys for a reaction after last week and I got one,” he said.
“It was a massive improvement. I don’t think the game was out of our reach but it’s just our execution that’s letting us down.”
It will be Grady’s first Welsh derby, and he is relishing the occasion, which will be boosted by being held at Cardiff Arms Park on Sunday afternoon.
“I’ve not been involved with a Big Welsh Derby before and I am quite excited,” he added.
“The whole atmosphere is going to be fantastic especially as there are games on beforehand. I’m told it could even be a club record crowd.
“I know he’ll have his players well-drilled and they’ll be looking forward to playing in this game as much as we are. It should be a fantastic encounter.”