Chelsea won the game 2-0 but Crouch allowed his frustrations to get the better of him in the second half and lunged a two-footed tackle on Mikel Obi.
The result was a straight red card by referee Martin Atkinson much to the annoyance of Crouch and then Liverpool manager Rafael Benitez.
More than 14 years after the incident, Crouch has conceded he was wrong as he looked back on his career.
"The worst tackle I ever did was on Obi Mikel. Liverpool against Chelsea in the Carling Cup," Crouch told BBC 5 Live Sport.
"The whole game I’ve been receiving balls and he’s been basically told to mark in front of me. So the centre-half is behind me, and him and, here.
"And [Mikel is] basically standing all over my toes and I’m trying to chest things away and he’s putting his head in my face and his elbows around me all game.
"I’ve been telling the [referee] all game, all game, all game and I’m getting nothing. We’re about 70 minutes in now and it’s been going on all game.
"And it’s happened again and the ball has broken off and another one of these elbows and things he’s done to me – the ball’s broken there just posted perfectly and he’s facing the stand and obviously I’ve switched, lost the plot and tried to take him out basically.
"But I’m not proud of this if he’s listening to this, which I think in no way he’ll be, John Obi Mikel I'd have to apologise because the red mist was that… It was like an out of body experience."
"After the game, I thought he’d dived! Afterward, I got back, and I thought I’ll have a look back at that tackle. I had a look and I thought, oh no!. That’s in fact three red cards," Crouch continued.
"What on earth was I thinking? It’s just something that I can’t explain. He’d been winding up the entire game and now I just completely lost it."
