Rafa Benitez’s men headed into the clash with already-relegated Villa on Saturday knowing that a victory against the rock-bottom outfit, who have lost 12 of their 19 home games, would significantly boost their chances of avoiding the drop.
Benitez’s men though missed a glut of chances and had to settle for a draw, while Sunderland defeated Chelsea 3-2 to climb out of the relegation zone and drop Newcastle into the bottom three.
And if Sunderland defeat Everton at the Stadium of Light on Wednesday night then Newcastle will be relegated.
“We never really looked under threat defensively, but we never really had that killer instinct going forward,” Colback said.
“I can’t really answer the question as to why – we knew how big the game was. It’s difficult to put your finger on it. We knew how important it was.
“I don’t know whether a bit of fatigue kicked in or what, but we weren’t quite as energetic as we have been.
“Obviously the beach balls and inflatables getting put on the pitch made it difficult. We didn’t really get momentum in the game.
“It was stop-start. Everyone’s gutted. It’s obviously out of our hands now but we just have to pray Everton do us a favour.
“They’re a good side, so there’s no reason why they can’t go to Sunderland and get a result.
“Then we’ll back our home form to get a win, and then you’re looking at Sunderland’s result again.”