McDermott was unhappy with the performance more than the result and admitted he had not seen it coming after some good work in training.
Craig Westcarr’s 12th minute volley proved the only goal of a disappointing contest and condemned Leeds to their third defeat in five pre-seasonfixtures.
McDermott said: “We’ve got to move on really quickly after a performance like that and get ourselves ready for the next one on Tuesday.
“I didn’t see that one coming, I was really disappointed on Saturday.
“We’d built up a bit of momentum, we had the three games out in Slovenia and we’ve trained well.
“There wasn’t enough energy in the team. When you play football you have to run, you have to go beyond defenders.
“The players have to do the right things when they haven’t got the ball so they have to make sure that they get the details right.
“You are always concerned after a performance like on Saturday but you cannot get carried away, I never get carried away with a great victory and I never get carried away with a bad performance like Saturday, but we don’t want to see too many of them.”