"I actually had the ball, I got to it first," he told the Birmingham Mail. "He (Chopra) came in and that's what took it loose out of my grasp. I had both hands on it.
"I think he connected with the back of my head with his knee and I didn't quite know where I was for a few moments after that. Nigel Spink (Blues' goalkeeper coach) told me at half-time that they were shouting for a penalty but I thought it should have been a free-kick to me."
On the state of the picth Doyle continued
"It wasn't nice at all. Wherever you kicked the ball, you were kicking it out of water. It had been raining constantly before we got to the ground and just carried on, there was no let-up. The pitch was soaking wet.
"It wasn't just that, but it was heavy and squidgy underfoot. You would be literally sliding about."