Sunderland captain Luke O'Nien concedes Newcastle proved too strong on Saturday.
Newcastle were comfortable 3-0 winners at their FA Cup opponents.
"It's really difficult to process because it's quite fresh just after the game," said skipper O'Nien.
"Emotions are still a little bit scattered and I'm still trying to process them all. It's disappointing that we didn't come away with the win.
"It's a difficult one to take because there are high expectations from everybody. There was the hope before the game which we all kind of lived and to not match that up with the win or the performance was tough.
"You have to be gracious in defeat and say Newcastle were the better team."