The Blues eventually won 4-1 on Saturday, with Abraham netting the equaliser.
And the 23-year-old admits he was among a group of players who called for cool heads after finding themselves one-nil down.
"A couple of us are used to Sheffield United and their style of play, like myself," he said.
"I have played against them a few times before so I always knew it was going to be hard to break them down.
"They had the first goal so we had to keep our heads, we spoke and said relax and hopefully the chances will come, and I scored soon after."
He added: "We have brought in new players and we are understanding each other more.
"We have self-belief now, the belief is back, the confidence is back and we hope we can keep it going."