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.
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."
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."
|Jones: England back on road to being world´s best|
|Germany survive in Sochi but questions remain|
|Germany 2 Sweden 1: Late Kroos winner brings Low´s men back from the brink|
|Perisic dreaming of matching Croatia´s France 98 heroes|
|Veron questions Sampaoli for leaving Icardi out|
|Southgate won´t blame injured Alli for playing through pain barrier|
|Travelers Championship: Course invader drives Rory McIlroy and crowd nuts|
|Saul tells Atletico to renew Oblak deal after Griezmann´s new contract|
|Course invader sends McIlroy & crowd nuts at Travelers Championship|
|Saudi Arabia v Egypt: El Hadary eyes history in dead rubber|
|Referee declines Cheika invite after Australia´s series loss to Ireland|
|Griezmann, Mbappe can eclipse Henry, claims Trezeguet|
|Nawalka hopeful of Glik return against Colombia|
|Mexico outsmart South Korea to join Croatia as unheralded World Cup threats|
|´No drama´ for Southgate after England team sheet leak|
|Hend caught by five in Pulheim as Bjerregaard goes low|
|´Little Pea´ Hernandez hits big Mexico milestone in World Cup win|
|Modric and Rakitic the best midfield in Russia - Corluka|
|Cipriani and Farrell ease pressure on Jones as England avoid SA whitewash|
|South Korea 1 Mexico 2: Hernandez nets landmark goal as last 16 beckons|
|Ozil and Khedira axed by Germany|
|Djokovic plans to use two rackets against Cilic after reaching Queen´s final|
|World Cup of penalties? Russia surpasses Brazil after VAR introduction|
|Neymar ´fully recovered´ but Brazil coach Tite has thigh injury|
|Hansen claims France ´clutching at straws´ after another referee controversy|
|Douglas Costa, Danilo out of Brazil´s Serbia clash|
|Hamilton claims 75th pole as Mercedes dominate in France|
|´Mentally strong´ Salah will overcome World Cup disappointment, says Mane|
|Pekerman contemplating unleashing James and Quintero together|
|Schmidt hopes Australia furnace will produce Ireland diamonds|
|I´m missing practice, but it´s OK - Federer ready for Coric|
|Spain v Morocco: Alba makes case for the defence|
|Team-man Lukaku firmly in the race for individual prize|
|Belgium 5 Tunisia 2: Lukaku and Hazard shine as Red Devils run riot|
|Leaked England team gives Panama no advantage, insists Gomez|
|Mane and Senegal holding no fear for Japan|
|Murray to meet Wawrinka at Eastbourne|
|Nigeria goalkeeper Ikeme in remission after year-long cancer battle|
|Lukaku breaks Belgium record against Tunisia|
|Iran v Portugal: Team Melli bullish over qualification chances|
|Mauresmo to be France´s first female Davis Cup captain|
|Maradona angry at Argentina World Cup performances|
|Ireland cap stunning season with series win over Wallabies|
|Uruguay v Russia: Selection posers for already-qualified pair|
|Federer scraps his way to yet another Halle final|
|Lunin rejected ´3,000 offers´ to join Real Madrid|
|On your bike! Iceland physio sent home after cycling accident|
|Not just Real Madrid interested in Fekir, says Aulas|
|France frustrated by officials again as All Blacks complete sweep in style|
|Jose Enrique reveals brain tumour surgery|
|The referee was a disaster, fumes Matic|
|Lakmal to captain Sri Lanka in Chandimal´s absence|
|Alli back in England training|
|McIlroy, Watson plotting moves as Harman leads Travelers Championship|
|Tearful Neymar is a joyful boy, says Jesus|
|Ruiz: Coutinho has the same quality as Neymar|
|Kovacic announces intention to leave Real Madrid|
|Red Sox edge Mariners in 34-hit extravaganza|
|Marquez asks Mexico fans to ´let them rest´|
|Fabregas hopeful of Spain recall|
|Milinkovic-Savic plays down Juventus speculation|
|Rashford inspired by Ronaldo|
|Messi is not a leader, he is no Ronaldo, claims Petit|
|Better than Ballack? Hodgson backs Loftus-Cheek to shine against Panama|
|Svitolina and Garcia suffer upsets|
|Walker responds to Ferdinand criticism|
|Djokovic still hungry for more after reaching major milestone|
|Ellis drop goal earns Castleford dramatic win|
|Nigeria hero Musa unsure on Leicester City future|
|X marks the spot - Granit´s rocket sets World Cup first|