The Gold Coast skipper has been limited by back and soleus problems that have restricted his time on the training track.
But the Brownlow medallist has now resumed training and McKenna is confident he will be cherry ripe for round one.
"It's not ideal, but Gazza's been around the block long enough to know what's needed, so I'm more than comfortable he's in good nick," McKenna said.
"His training in Arizona (in November) was fairly solid and he got a really good base going. He's really happy with where his body is at, and if he's happy, I'm happy."
Ablett has missed just four games in his two seasons with the Gold Coast, including two with a knee injury last year following a collision with Brisbane Lion Andrew Raines.
He was nursed through the early stages of the pre-season with a back niggle, and sustained the soleus strain after returning from the Christmas break.
Ablett has resumed running this week and is expected to be back to full load shortly.
McKenna said his young team was now better equipped to take some of the workload off Ablett, whatever capacity he played at.
"We know how hard he's had to work to generate what he has over the last two seasons, and now you can see already in this pre-season David Swallow, Dion Prestia, Kyal Horsley, Karmichael Hunt (improving) ... all of a sudden Gary is starting to be cut some slack," McKenna said.
"Instead of doing all the grunt work, he can start picking up some of the cream. That's the exciting part.
"It's the third pre-season and these boys are ready to start shouldering the load."
Despite winning just three games last season, Gold Coast showed some of their better football when Ablett was injured, pushing Fremantle to seven points and leading North Melbourne at half-time in the two matches he missed.
"With the amount of training (physical performance manager) Stephen (Schwerdt) has put into these blokes, they're going to endure for longer. That's going to enhance our team performance and I think it's going to enhance Gary's performance as well."
Michael Whiting covers Gold Coast news for AFL.com.au. Follow him on Twitter: @AFL_mikewhiting
