Pools have lost five games in a row after the Magpies came from behind to win 2-1 at Victoria Park.
Harrison’s side are now eight points adrift of the top seven and the former TNS chief pointed out that his side’s defending must improve if results are to change.
He told Pools PlayerHD: “It doesn’t matter who you play, they’re always going to have a few opportunities but you have to see them off, shut the back door and go forward again – we just didn’t defend like we should do, it was poor.
“I felt like we were in cruise control and on top of the game, creating opportunities – the second goal would have killed them off but we can’t a be a team that needs to score twice to win a game.
“We want to go looking for the second goal and today we could have had three or four but there are going to be times where you have to win the game 1-0 – today we just showed our frailties.”
For more news, reaction and action from across the National League, like us on Facebook and follow us on Twitter and Instagram.