Bennell was arrested and charged with disorderly conduct and failing to obey a police officer on New Year's Eve in his home town of Mandurah, south of Perth.
The Suns have said they will wait until Bennell's court case next Tuesday before determining whether the incident will require a punishment for the classy midfielder.
While McKenna conceded indiscretions were unavoidable with young men, he insists the culture of the Suns is not in question.
"When the boys go home to have a break and let their hair down, things will happen," McKenna said in a press conference on Monday.
"You are always disappointed when your club gets shown in a bad light.
"But the AFL, the AFL clubs themselves, coaches, senior players and all the playing group have to take responsibility and continue to drive for perfection.
"In the scheme of things (Bennell's incident) is not great but our pre-season has been good on and off the field and we will continue to move forward."
McKenna said the Suns were "clearly not" developing cultural issues and declared "it's not an issue whatsoever".
"The playing group will (get the chance to) air their grievances and we will come down after the court case and speak to Harley about all that," McKenna added.
"We want to make sure we become a club full of cleanskins and that's what you strive for."
The incident follows fellow youngster Trent McKenzie who added to the club's woes when he was suspended for turning up late to a recovery session last season following a night out.