McKenna was clearly unhappy that Brown's 205-game career ended last week when he was sacked for breaking teammate Steven May's jaw in a recent incident in Los Angeles.
The former Hawthorn premiership player's on-field aggression led to him being suspended for a total of 14 games during his time with the emerging Suns.
However, McKenna said he had no regrets over Brown's recruitment when he addressed the media about the veteran's dumping for the first time on Wednesday.
"It was disappointing, yeah it was," he said of Brown's incident.
"But clearly it was a pass (mark for his tenure).
"The incident was disappointing but everything he did for us a football club in its infancy was exactly what we asked for."
Brown, 30, had just finished a pre-season training camp in Arizona with the Suns ahead of what he believed would be his final year in the AFL when he struck May outside a Hollywood nightclub.
It came almost two years after the 2007 All-Australian was dumped from the Suns' leadership group for his part in a Thailand bar brawl in September 2011.
But Brown - who was suspended for a total of 29 games from 14 charges in his career - said after his sacking he did not believe he had anger issues.
McKenna was adamant Brown had provided a valuable service to the club.
"On field yeah, the suspensions hurt and there was the incident and it was disappointing to lose a player like that," he said.
"But what he has done is shown our players about making a 50-50 ball a 51-49 ball and he did that.
"He crossed the line and he got suspended, we understand that throughout the course of a football season, but he showed our boys the way to be passionate about the contest.
"As much as I and the other coaches can talk about it, you have got to be able to play living and breathing it, and he was a great example for the team."
The Gold Coast have lodged a request with the AFL to have a rookie elevated as Brown's replacement on the senior list.