Just take it easy on the Highlanders captain if you go in for a high five when you see him.
Harmon now sports a massive scar on his right palm after sustaining a nasty cut in the game against Moana Pasifika in Tonga.
It got infected, forced him to have two surgeries and left him in hospital for four days.
"It was less than ideal," Harmon dead-panned this week.
"I was just pretty unlucky, really. It’s not too bad. If I don’t catch a ball or throw a bad pass, I can’t really blame it on that."
While his hand is one thing, the real topic of interest is Harmon’s future.
It is widely believed the respected loose forward, ripe to test the market at the age of 29, will end his glittering Highlanders career after this season and sign a lucrative deal with a leading Japanese club.
Specific questions about his future were off-limits this week, and Harmon played a straight bat when asked about the prospect of the trip to Canberra being his last in Highlanders colours.
"I haven’t really thought about that at all.
"If I’m going over there preparing for my last game then I’m not in the right mindset."
The Highlanders are heavy underdogs when they meet the Brumbies in the quarterfinal, but they do not want their season to end tomorrow night.
All he sensed around him was genuine excitement and focus, Harmon said.
"It’s awesome to be here. It was one of our goals coming into the season.
"We’re one step closer to where we want to be. These games are different. There’s way more pressure. It’s those little details that are going to matter in our game, and we’re excited and can’t wait to get into it.
"Everyone’s stepped up. Everyone’s ready and excited to be playing."
Harmon has been around long enough to know the Brumbies have few weaknesses.
"We know we’re going to be in for a battle because the Brumbies have been playing some awesome footy.
"Great set piece, attacking backs — we’re ready for an intense game with lots of pressure.
"Their pack has got a lot of Wallabies who play tough and carry hard. Their lineout is one of the best in the competition. And they’ve got a Wallabies 10 who really controls the game."
The Highlanders needed to stay particularly disciplined, Harmon said.
A mid-season change led to Harmon sharing the captaincy with prop Ethan de Groot - perhaps paving the way for the giant Southlander to be a permanent leader next season — and the incumbent skipper has enjoyed it.
"It’s going good. Nothing’s really changed.
"Ethan’s always been a key leader in our team. He’s doing an awesome job. He’s stepped up as a leader, he’s a Highlander man, a great southern man and the boys really get behind him.
"He’s got a lot of emotion around playing for this team and this jersey, and he gives a lot of that to the lads."
