James Rowe gave an honest assessment after the Spireites slipped to a second successive defeat with a 2-1 loss at home to FC Halifax Town on Tuesday night.
He said: “We started brightly before their goal. Their goal came out of nowhere and it was poor defending. We didn’t react quite right to those mistakes.
“It was poor defending for the two goals, that’s why I made the change at half time. We were lethargic. We can’t concede goals like that which is what we’ve done well at.
“In that game we hardly had any defending to do. The lads know themselves; we’ve had words in there.
“We’ve got to give some credit to Halifax. They grew with confidence from their first goal, but we won’t be losing at home like that again I can assure you.”
Kairo Mitchell scored his first goal for Chesterfield since joining from King’s Lynn Town and the manager was really pleased to see the striker get off the mark.
“I’m really pleased for him,” Rowe said. “He deserved that with his hard work. He came out in the second half after a sticky first half.
“He knew he needed to be better and get a hold of it better. He needed to make more of an impact up there and he deserved his goal.”
James Montgomery came into the starting XI, making his debut after signing from Gateshead, replacing Grant Smith in goal.
Commenting on the decision, Rowe said: “I wanted to take a look James. He’s experienced. I thought it would be a good game to see him in. I didn’t think he would have a lot to do; I think he made one save.
“His distribution and communication were good. It was a tactical change, and it was the decision that was made.”