The Premier League newcomers were beaten at the last minute of their home clash against Bournemouth, going down 2-1.
McKenna felt that a goal disallowed in the first half, which would have given them a 2-0 lead, was a turning point.
“It’s a devastated dressing room today,” McKenna said post-game.
“I thought there were so many good things in the game, so many good things in the performance, the commitment levels were outstanding. Some of our play was really, really good. Right up to the point of their first goal, really.
“And it’s a disappointed group because we felt like we deserved to take the lead, felt like we had a second goal which was harshly overruled, to be honest. Felt like we had chances in the second half.
“It was always going to be a difficult second half, especially with the quality of the subs that they were bringing on, but we felt like we defended well, we had chances to get the second goal and on 86 minutes, I think we were in as much control of the game as you can be at 1-0 against a team of that level. There wasn’t a huge threat, we were defending well.
“And a really poor first goal from our point of view changes the momentum of it and then they have the momentum and the quality to execute really well for the second goal.
“It’s an extremely disappointed group, I don’t think we got what on an individual level or as a squad we deserved from the game.
“But that’s football and as much as it’s a devastated dressing room at the moment, I know what the reaction will be. I believe in what the reaction will be and I believe we will be back fighting next week.”
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