David Marshall was left to rue boucing the ball when Samuel Eto'o was stood next to him allowing the forward to set up Eden Hazard for the first of Chelsea's four goals.
Cardiff were leading 1 - 0 at the time and doing a good job of frustrating their opponents
"I am not sure if the linesman, referee think maybe I have dropped the ball thinking he's [Eto'o] not there, but I knew he was there and I have bounced it so hopefully we can get it cleared up," Marshall told Sky Sports News.
"But it doesn't help us now, it is just disappointing as the boys had done great in front of me and we were in such a good position.
"I am just gutted to let them down.
"As I say I shouldn't have bounced it and it probably is my fault."
Marshall's opposite number Petr Cech had little sympathy for the Cardiff keeper and believed the referee got it right. Even though the law states Marshall was entitled to bounce the ball. A foul should have been given and the goal disallowed.
"It's always a difficult question, when you lose control or not lose control," Cech said. "What I know is that if you throw the ball to kick it out, nobody can touch you because it counts as one motion.
"In terms of bouncing it's not one motion, so it's totally up to the referee to decide whether the goalkeeper had control of the ball or not. The referee had the perfect view of it, he was very close and he decided to give it.
"In this case you have to go with the referee. It's an unusual situation, but as long as the referee is happy with it, the goal is in. As a goalkeeper you make sure when you have control of the ball, you look around and make sure nobody can touch it.
Source: Cardiff City Online