McKenna said he made the playing group watch the inept first quarter of Saturday's 54-point loss to the Brisbane Lions while listening to the scathing commentary of premiership duo Alastair Lynch and Jason Dunstall.
He said the Suns had lost any credit they had gained this season with a "cataclysmic" performance.
However, rather than fade off into the sunset in 2014, McKenna said it was now up to his men to fight.
"We weren't hard enough and we weren't disciplined enough," McKenna said of the Lions performance.
"For them to experience that (review) and listen to the words of two fellas who were commentating that have combined won seven premierships, listen to what they say and what they're talking about us like (was good for them).
"Those 10 good things that you've earned that respect, in one fell swoop it just gets taken out of your bank. We've just got to start again."
With two successive losses – and six from its past eight - Gold Coast has dropped to 10th place, but only percentage behind eight-placed Adelaide.
McKenna said he still believed they could make the finals, but it would start with actions against St Kilda on Saturday night.
"Everything's been going rosy. Well here's a dip. What do we do now? Do we go down to the watercoooler talks and cry on each other's shoulders or do we stand and fight? That's certainly what I'm all about," he said.
"We're all in this together. You've got to help each other out. We're going to fight our way out of this, we're not fading out of the season.
"We'll determine our own destiny, no-one else."
McKenna said he had spoken to ruckman Zac Smith about a bizarre first-quarter incident where he stood idly beside Lion Lewis Taylor as he calmly snapped a goal from the top of the goalsquare.
"Zac's line was 'I didn't know what I was doing.' My first response was 'clearly'," McKenna said.
"But what you have to do is coach him through it."
Smith (ankle) and Charlie Dixon (groin) are both seeing specialists on Tuesday to determine the full extent of injuries sustained at the weekend.
They will miss against the Saints and, worst case, could miss the remainder of the season.
Twitter: @AFL_mikewhiting
