The PNE boss was always planning to ring the changes for the League Cup third-round clash but has challenged those who come into the team to keep their places for Friday night’s derby with Wigan.
North End capitulated in the last few minutes of the 5-0 defeat to the Bees at Griffin Park.
They only conceded the second goal in the 74th minute then shipped three goals in the 84th, 85th and 87th minutes.
Grayson described the display in the closing stages as ‘kamikaze’, with the side down to 10 men after Marnick Vermijl went off with a hamstring injury.
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When Vermijl departed, all three substitutes had already been used.
The Belgian right-back will miss the Bournemouth game and likely to be out for a few weeks.
A number of his team-mates from Saturday are also set to join him on the sidelines when Preston head south to face Eddie Howe’s men.
Grayson, pictured, said: “We had discussions in the dressing room after the game.
“We now have a game on Tuesday night against Bournemouth which is a tough task. I was going to make changes for that game anyway but the players who come into the team will have the chance to try and stay in it for Wigan which is our next league game.”
Grayson said sorry to the 889 North End fans who were in the away end at Griffin Park for the manner in which the side folded late on.
“We can only apologise for what they saw in that last 15 minutes,” he said.
“Up until then, we were good and it looked like being a good away performance.
“But that crazy last 15 minutes made it the shocking day it was.
“We apologise to the fans who spent a lot of money going down there.
“They have seen us go from the position of being very good the other night against Cardiff to something at the other end of the spectrum.”
It was Grayson’s heaviest defeat as Preston manager and the club’s biggest since December 2004.
“We have never been beaten by five goals since I have been here,” said Grayson.
“The players did not play with their heads, they were trying to get back into the game when it was never going to happen.
“If you give Brentford time and space to play, they can beat anyone.
“Make it open against them and we might have got picked off with 11 players.
“When we made mistakes with 10 men, we got punished. With 10 men, we needed a back four with another bank of four in front of them to be solid.”