"I don't think because we haven't scored against Charlton will have an effect on what happens on Wednesday," he said.
"The ground will be a lot noisier come Wednesday, I'm sure the boys will play at a higher tempo.
"We know what the press are going to say because we have been getting a lot of 1-0 results and on Saturday we couldn't find that breakthrough. We've just got to keep creating the chances and hopefully a few breaks will go our way and the goals will come.
"We've definitely got goalscorers in the squad. I'm sure it is only a matter of time before the goals start going in.
"It was a 1-0 game on Saturday - if Robbie's goal had stood, we have seen it and it was onside. The linesman has given offside for Djibril but he wasn't interfering with play. But sometimes decisions don't go your way. We need to be more clinical in front of goal on Wednesday.
"Robbie was close to getting into the Kop. It would have been nice for Robbie to get the goal and it would have given him a lot of confidence. But he is playing well and working hard. He told me that's his first 90 minutes since last May, and he's looking good considering the amount of football he has been playing."