Ablett has carried an enormous workload over the first two seasons of the Suns' existence, easily winning the best and fairest both years and topping almost every statistical category at the club in 2012 - from contested possessions to clearances to goal-kicking.
But McKenna feels the time is right for the 28-year-old Brownlow medallist to defer the tough stuff to his younger teammates.
The Suns' coach wants to use Ablett as more of a finisher than a provider.
In two matches Ablett missed last year, the Suns ran Fremantle to within seven points and led North Melbourne at half-time before fading.
The captain rested against the Sydney Swans last week, and McKenna said he felt the young midfielders had shown enough to take more responsibility.
And Ablett has to let them do so.
"I think what Gary's seen over the pre-season, with the way these boys have covered the ground and put it into on-field performances, that they're ready to do that," McKenna said.
"It's going to be hard for him to adjust his style of football, but I think that's going to be a pleasant thing to be coaching going into this season, how the boys can shoulder some of the slack that Gary's now prepared to let go."
McKenna said allowing Ablett to stay clear of the contested footy more often would add another year or two to his career.
He said it would also make his teammates better players, and ultimately, the Suns a better team.
"The pleasing thing for us is he'll be on the end of a chain of possession instead of starting it off for us. I think that's a good thing for him personally, but us collectively.
"It's going to be tough for Gaz. That's going to be an adjustment for him because his natural thing is he wants to win and the best way (in his mind) to do that is to get his hands on the ball.
"I don’t think anyone in the AFL would deny him doing that, but what's going to help him play longer and make us better is him to allow Jaeger (O'Meara) his turn to go in, Dion Prestia his turn to go in, David Swallow his turn to go in, Michael Rischitelli and the names go on.
"That's an adjustment. It's not going to be easy for him."
McKenna said Ablett was in front of where he was this time last year, despite calf and back problems during the pre-season.
"I would have thought for the competition that's spooky," he said.
"I think he's ready to rumble."
Gary Ablett is a midfielder in NAB AFL Fantasy. He averaged 124.7 points in 2012. Register your team at our AFL Fantasy Hub.
Michael Whiting covers Gold Coast news for AFL.com.au. Follow him on Twitter: @AFL_mikewhiting