It was not the start Pools wanted to their Vanarama National League season as they slipped to a surprise 1-0 home defeat to Dover.
Harrison talked openly about the loss after the match and thinks his squad will be fine once they ease up a little.
“I don’t think we deserved to lose the game,” said the new manager. “That’s not to say we did enough to win it, as we didn’t.
“Perhaps it was because it was the first game, and a little bit of nerves were there. We were a bit too worried about not losing.
“I think once things settle down, we’ll be competitive. We needed to relax a little bit and we move on to Tuesday night now.”
On their game at Macclesfield, Harrison said: “They’ll be delighted to have won over at Wrexham on the first day of the season.
“We know it’ll be tricky, they’re a big club at this level so we’ve got to perform.”
On Saturday, Pools play at Maidenhead United and the game is live on BT Sport.