Justin Thomas did not want to "compare Cadillacs" when asked which of Tiger Woods or Phil Mickelson would be pulling off the more significant achievement with victory at the U.S. Open this week.
Woods is looking to win his 15th major and first since his playoff triumph over Rocco Mediate at the 2008 U.S. Open.
Meanwhile Mickelson, having finished runner-up at the U.S. Open six times, has eyes on completing a sweep of all the majors, a feat Woods has already achieved.
MORE: Tiger Woods: I've missed playing the U.S. Open
Speaking at a media conference, Thomas, who clinched his first major at the 2017 US PGA Championship, responded to a question about Woods and Mickelson's prospective achievements at a media conference by saying: "You're comparing Cadillacs there, you know.
"It's not - they're both pretty - it would be unbelievable achievements.
"I mean, obviously, for Phil to complete the Grand Slam would be tremendous. And then, you know, if and when Tiger does win more majors, it's just another major.
"It's hard to compare and say one would be better than the other. I think you just would have to recognise greatness if either one of them happened."
A decade old.
— PGA TOUR (@PGATOUR) June 12, 2018
Like a fine #LiveUnderPar pic.twitter.com/fRCqyNylir
Shinnecock Hills is expected to provide a sterner test than other U.S. Open courses in recent years, though it has been extended to 7,445 yards.
Asked if being a long hitter will be important this week, Thomas added: "Putting it in the fairway is definitely going to matter more than anything, but it's not playing - at least when I played, it wasn't playing very fast by any means. It was good. You know, the ball would roll a little bit, but it's not like you're hitting two-irons that are going 300 or anything. For that reason, I'm not using a two-iron this week.
"It's just not a place where you get the ball on the ground and it rolls forever. They had some good rain last week, and that's just how it is right now. If they continue to get the conditions they want or how firm they want to get the course, they can get it like that.
"But, I mean, I would like to think I have an advantage if I drive it well, versus an average driving distance person. Hitting eight or nine-irons into these greens, as opposed to six-irons, is a big deal.
"At the end of the day, like every U.S. Open, it's going to come down to just total control of your golf ball and minimise the mistakes."