The PNE gaffer took to PNEPlayerHD to signal his frustration following North End's 1-0 defeat to Ipswich.
The PNE manager opted for the same XI that beat QPR just seven days ago, but Grayson was frustrated that his side couldn't take that win into today's game.
After the game, Grayson offered an honest assessment to PNE PlayerHD.
"There wasn't a lot in it but overall in the 90 minutes, we didn't do enough to win the game," he said.
"We set high standards from last week and we didn't maintain that today. You know what you're going to get from Mick (McCarthy's) teams - they're going to be on the front foot and they're going to ask questions of you and we didn't deal with that well enough.
"The midfield didn't win enough second balls and we didn't do enough to create enough chances so we're disappointed."
The only goal of the match came just after Jermaine Beckford pulled up with a hamstring injury seeing the forward replaced early on; and although Grayson felt it didn't help the situation, he refused to use that as an excuse following today's loss.
"He got a knock to start with and then he was feeling his hamstring," told Grayson.
"We've got a two week break now so he shouldn't be out for too long. It's something we didn't need but that's part and parcel of football, we've just got to make sure we do what we know we can do.
"When you come here, you need to stop the opposition like we did against QPR. It just looked like they were on the fron foot more and asked more questions.
"We've got two weeks now to get some work into the players and start getting some better results.
"Too many players let their standards slip today."
To hear more from the Preston North End boss, as well as the post-match thoughts of Tom Clarke, watch the interviews via PNE PlayerHD by clicking here.