Muric has been enjoying a very good season for the newly promoted club, but had a poor game in a 2-1 loss to Bournemouth.
However, McKenna does not want to throw his shot stopper under the bus, given he has saved the team more than once this term.
McKenna said: “We support all of our players and we know that mistakes are going to be made over the course of the season.
“Aro is still in his first few months at the football club, we think he's an extremely talented goalkeeper. I have to say, I think he's got attributes to his game that are top, top class.
“He's also very young for a goalkeeper and settling into a new club, so there are things and areas of his game that he's working really, really hard on, and we're fully engaged in that process with him.
“Obviously he was disappointed with Bournemouth's first goal on Saturday. With any goal that goes against you, it's never just one thing, there were a couple of other things as a team and as individuals within the team that we could have done better to stop the goal.
“But he's a good professional in terms of how he works here day-to-day. He's training well. He's adapting to the demands that we're putting on him well in many aspects and he's really keen to help the team. I know he's going to look to do that in the games ahead.”
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