Gary Kelly missed the Arsenal defeat with a hairline ankle fracture which he suffered in training on Saturday.
His absence meant England U-20 international Richardson stepped in and he made a big impression and despite the heavy defeat, he will have another chance to impress at St James' Park on Wednesday against Newcastle.
He said: "I feel very confident that I can do a job now. At the age of 16 I first got told to be patient and this is my chance to show what I can do. I hope to grab that chance with both hands.
"The cup result against Arsenal was disappointing. The 4-1 scoreline flattered them, but I think we will get out of trouble in the league. Eddie Gray believes we can and so do all the players.
"I think it is just a matter of when we get out of trouble, not if we do."
His absence meant England U-20 international Richardson stepped in and he made a big impression and despite the heavy defeat, he will have another chance to impress at St James' Park on Wednesday against Newcastle.
He said: "I feel very confident that I can do a job now. At the age of 16 I first got told to be patient and this is my chance to show what I can do. I hope to grab that chance with both hands.
"The cup result against Arsenal was disappointing. The 4-1 scoreline flattered them, but I think we will get out of trouble in the league. Eddie Gray believes we can and so do all the players.
"I think it is just a matter of when we get out of trouble, not if we do."