St Kilda was merciless against the Suns last season, winning by 92 points in round two and by 95 points in round 11.
But McKenna said that was water under the bridge and of little consequence to his young team.
He said it was important to start both Saturday's game and the season in general on a positive note.
"There's no more extra points on it (round one), but what it adds from a confidence and belief point of view I think it's fairly significant," McKenna said.
"We're a year older, a year wiser, a year fitter, stronger, faster. We can look at the two 90-point whackings last year and it probably gives St Kilda more confidence.
"What our players have to understand is we're a year older, we've got Tom Murphy in the side, we've got Greg Broughton in the side, (and) some players are in better form than last time we played St Kilda.
"When the siren goes and the umpire holds the ball aloft, all bets are off, all history is forgotten. It's about us making our new history, our new tradition of starting off at Metricon Stadium with a win."
After losing their first 17 matches at Metricon, the Suns started to right the ship late last season with successive victories over GWS and Carlton.
They will start Saturday's match with a three-pronged tall forward line of Sam Day, Charlie Dixon and Steven May against a St Kilda defence weakened by the loss of Sam Fisher and Sean Dempster through injury.
McKenna said he had briefly spoken to Jaeger O'Meara ahead of his highly-anticipated debut, and encouraged the footy world to be patient with the teenager.
"I can tell you how quick it's going to be, but until you get out there, it's probably twice as quick as what I can tell you. He's a very level-headed fellow and the good thing is he's been here for 12 months," McKenna said.
"He's a super kid, he's going to be a super player. My expectations are fairly low. At the end of the season we should judge him on whatever he has achieved, put another 30 per cent on it because he's going to do it tough for us (with so many young players around him)."
Michael Whiting covers Gold Coast news for AFL.com.au. Follow him on Twitter; @AFL_mikewhiting
