The American is making his first appearance in the biennial match and it will definitely be a baptism of fire with around 50,000 fans, the majority roaring on Europe, expected each day at the Marco Simone course.
Football-style atmospheres are what set the Ryder Cup apart from the polite etiquette of usual golf tournaments with missed putts and wayward drives often cheered as loudly as birdies.
Europe's players drowned in a sea of whooping and hollering American fans at Whistling Straits two years ago, losing 19-9. But at the Marco Simone course the boot will be firmly on the other foot even if many Americans have made the trip.
Harman knows that what is coming will be on a different level entirely to Hoylake where he led by five after rounds two and three and refused to buckle on a rain-hit final day, putting like a machine to eventually win by six.
Fans rooted for home favourites Rory McIlroy, Tommy Fleetwood and Spaniard Jon Rahm at the weekend and some heckled Harman with comments he described as "unrepeatable".
One goaded him by saying he did not "have the stones" to complete his maiden major victory. But Georgia's Harman, who hunts animals he rears on his home ranch on St. Simons Island with a crossbow and butchers them himself, proved teak tough.
"I don't think there's any way to prepare for it. I expect them to be as fervent and I expect to be at times overwhelmed by it, just like I was at The Open championship," Harman told reporters on Wednesday. "It was overwhelming at times.
"The best you can do is just acknowledge it and just move forward and try not to let it affect you. But it will affect you. You'd be silly not to think that - obviously the home teams in the Ryder Cups have been extremely successful, and a lot of that has to do with the fans.
"They can affect outcomes of matches. It's just our job to try to stay as present as possible and execute more than the other guys and see what happens."
Harman, headlined the Butcher of Hoylake by British tabloids in July, is one of seven major winners in the U.S. team with 15 titles between them. It is an embarrassment of riches for captain Zach Johnson, but then again American teams usually look better on paper than Europe but have not one away for 30 years.
Harman said he would rather be playing than doing Johnson's job. "I don't envy Zach at all. I'd be happy to play with any of the guys. They're all super talented and they've won a lot of golf tournaments and they're all very, very good."
