The 22-year-old Spaniard has barely put a foot wrong since turning pro after being the low amateur, tying for 23rd place at Oakmont Hills.
His results since then speak for themselves -- seven top five finishes on the PGA Tour and a maiden win in January at the Farmers Insurance Open have propelled Rahm into the top 10 golf rankings.
Plenty of talented young amateurs have impressed at major tournaments only to fade -- just ask Justin Rose, who tied for 4th at the 1998 Open Championship before initially struggling as a pro.
Rahm, however, has made a seamless transition to the professional ranks.
"Luckily for me, I've always been someone who likes to play under that pressure -- I like the adversity," Rahm told CNN.
"I like to rise above that because I want to have the most amount of fun. I think that's why every time I've been against the ropes or had to do something, I've been able to do it.
"I think it's just the competitiveness I have in me. I don't like losing, so i just put everything I've got into it."
Rahm combines a surety of mind with an imposing physical presence -- his 6-foot, 2-inch, 220-pound frame combines both power off the tee and touch around the greens.
"Jon doesn't have weaknesses," five-time major champion Phil Mickelson said following Rahm's win at Torrey Pines at the beginning of the year.
"Every part of his game is a strength. I think he's more than just a good young player -- I think he's one of the top players in the world."
Rahm to the fescue?
Rahm will need all that skill this week at Erin Hills in Wisconsin -- a 7,741-yard, par 72, monster of a course full of links-like undulations, perilous sand traps and punishingly deep rough.
The now famed fescue grass has had a rough time of it from some of the players this week -- US golfer Kevin Na's Instagram video vividly revealed the difficultly of finding a ball, let alone trying to hack one back onto the fairway.
Not everyone is complaining though. Rory McIlroy noted that the fairways at Erin Hills are generously wide compared to the traditional set up at US Open venues.
"I get that it's thick and whatever, but it's a hazard," McIlory said, Tuesday.
"It's a US Open, it's supposed to be a tough test. And if guys can't put it into play within a 50-yard zone I don't think they've got much to complain about."
The US Golf Association have since trimmed the rough on selected holes saying the wet weather forecast has forced their hand -- not the players.
Rahm, meanwhile, has chosen to steer clear of the rough during practice rounds.
"I didn't step in it," Rahm said in a pre-tournament press conference. "There's no need to injure my wrist this week before I tee off.
"It really looks very penalizing. Unless you get extremely lucky where you might be able to move it 120 yards, it looks like a 30-yard chip out to the fairway."
It's a measure of Rahm's new-found status that he is mentioned alongside the likes of reigning US Open champion Dustin Johnson, and former winners Jordan Spieth and McIlroy as a genuine contender.
Victory for Rahm would further boost Spanish golf after Sergio Garcia's emotional win at the Masters in April on what would have been Seve Ballesteros' 60th birthday.
"If in my lifetime if I can show and express half of what Seve did for the game of golf it will be a very accomplished career," Rahm said.
It's a bit early to start talking about Rahm in the same breath as Ballesteros but time and natural talent are on his side and so, it seems, is his temperament.
"It's been quite a journey," he said. "I feel nothing but excitement and accomplishment but I'm a little bit scared because I'm don't know how I'm going to follow next year after this year.
"But there's a long way to go ... I'm sure I'll be just fine."