Pete Cowen revealed he laid down the gauntlet to fuel Brooks Koepka at Shinnecock Hills and can see the American winning more majors after clinching back-to-back U.S. Open titles.
Koepka held his nerve in Long Island on Sunday to become the first man since Curtis Strange in 1989 to successfully defend the U.S. Open trophy.
Cowen, Koepka's short-game coach, warned the world number four he would not realise his potential unless the 28-year-old improved his attitude before he won his first major at Erin Hills last year.
The Englishman, who also coaches the likes of Henrik Stenson and Matt Fitzpatrick, issued another challenge to ensure Koepka was fully motivated ahead of his latest triumph.
Cowen told Omnisport: "I'd been to Memphis the week before last year's U.S. Open and watched him play all four rounds and his attitude and body language was very poor, so I pulled him to one side on the Tuesday at the U.S. Open and said, 'Look, you're not going to win anything with that sort of attitude.'
"I challenged him again this year by saying, 'You want to make sure you keep hold of that trophy, it's a big challenge to keep it so make sure you do.'"
Koepka has established himself as one of the top players in the world and Cowen said he can go from strength to strength.
"He is a very cool character, he doesn't get stressed, he doesn't show any temper, snap clubs... You won't know if he's made a birdie or a bogey on the hole before. He's able to dismiss whatever has happened before almost instantly," he added.
"I've worked with him for the last five years and he's been like that all that time.
"You would say he can win more majors, he's young enough, he's number four in the world now and when you are at that sort of standard you are always capable of winning more. He is very talented and believed in himself [at Shinnecock Hills]."
16 de julio 2018
|Familiarity with demands of Real Madrid an advantage – Lopetegui|
|Parmentier rallies to avoid Bucharest exit, Arruabarrena bows out in Gstaad|
|Steelers fail to sign Bell to long-term deal|
|Over 10 per cent of Croatia´s population welcomes World Cup heroes home|
|Thierry Henry quits pundit role to focus on coaching|
|France´s World Cup winners given heroes´ welcome in Paris|
|At the end we will see who is best - Ronaldo sidesteps Messi rivalry|
|Qatar? China? Ronaldo only has eyes for glory at Juventus|
|Proud Kane praises team-mates after Golden Boot win|
|The Open 2018 diary: Is that Tiger Woods? Harrington feels the Burn...|
|Porte targeting Vuelta after Tour de France anguish|
|Maradona madness, #WaistcoatWednesday, bruised Batshuayi - Alternative World Cup awards|
|It could be the best time - Martinez hints at Hazard Chelsea exit|
|England call up Billings as cover for injury doubt Roy|
|McIlroy on track for fitting major haul - Harrington|
|Froome plays down Thomas battle for Sky supremacy|
|Carnoustie record counts for little at The Open, says Fleetwood|
|I don´t see it - Napoli chief De Laurentiis plays down talk of Callejon-Suso swap|
|One or two changes required at Chelsea, says Sarri|
|Monaco confirm Golovin approach|
|Let´s keep making noise! - Serena dedicates Wimbledon run to fellow mothers|
|Full list of Open tee times|
|Fakhar inspires another big Pakistan ODI win|
|Spieth ´annoyed´ by re-watch of 13th hole|
|Kaka claims Ronaldo arrival will boost all Italian clubs|
|Spieth vows to be more artist than tactician in Open defence|
|Conte thanks Chelsea players, staff and fans|
|Rodgers: I´d love to play with the Packers to 40|
|Sevilla insist N´Zonzi will cost €40m|
|Hugill shows mystic powers with accurate World Cup predictions|
|World Cup 2018: FARE ready for post-tournament challenges in Russia|
|Woods grouped with Matsuyama and Knox at Open|
|Matthaus questions idea of French dynasty|
|Chandimal, Sri Lanka coach and manager banned for two Tests and four ODIs|
|Sassuolo demand at least €30m for Berardi|
|French media revels in ´crazy´ triumph|
|Mafi released on bail after alleged assault|
|Bierhoff must go! Berthold calls for Germany changes|
|Joshua to fight Povetkin in September|
|World Cup 2018: Goal-laden final adds to staggering World Cup stats|
|Runners and Ryders: Molinari impresses again as stars prepare for The Open|
|Macron to greet France team after Champs Elysees parade|
|Casillas and Suarez critical of VAR after World Cup final|
|TMO protocol clearly not working, says SANZAAR|
|Americans seek joy of six at Carnoustie, Rose out to end wretched run - The Open in Opta facts|
|Ronaldo arrives in Turin for Juventus medical|
|Stone: I had no idea what my score was!|
|The Open: A look back at Van de Velde´s Carnoustie calamity|
|Rakitic proud of ´brother´ Modric´s Golden Ball award|
|Serena can surpass Court, but Graf was the real target - Krajicek|
|Ronaldo moved to remain motivated - Kaka|
|Silva confident on Everton transfer targets|
|Golden Boot winner Kane aims to break August hoodoo|
|NFL training camp 2018: Contract holdouts and where they stand|
|Guardiola took me to another level - Alaba|
|Madrid selling Ronaldo a ´historic error´ - Calderon|
|MLS Review: LAFC, Atlanta held at home|
|Stones will watch re-runs of England´s World Cup matches|
|Ferdinand challenges Mourinho to unleash Pogba at United|
|Mbappe: I´m staying at PSG|
|Former NHL goalie Ray Emery found dead|
|Pirates secure five-game sweep of Brewers with walk-off win|
|WATCH: LeBron receives standing ovation at Lakers´ summer league game|
|Tony Romo wins celebrity-filled American Century Championship|
|McGregor praises Putin after attending World Cup final|
|Open-bound Kim claims maiden title with eight-shot triumph|
|Eagles running back Sproles plans to retire after next season|
|World Cup winner Rami retires from international football|
15 de julio 2018
|Wimbledon champion Djokovic did not expect grand slam glory so soon|
|Ibrahimovic praises Pogba after World Cup final display|