HARTFORD, WI - JUNE 15: Jason Day of Australia and caddie Col Swatton walk to the 18th green during the first round of the 2017 U.S. Open at Erin Hills on June 15, 2017 in Hartford, Wisconsin. (Photo by Ross Kinnaird/Getty Images)
HARTFORD, WI - JUNE 15: Jason Day of Australia and caddie Col Swatton walk to the 18th green during the first round of the 2017 U.S. Open at Erin Hills on June 15, 2017 in Hartford, Wisconsin. (Photo by Ross Kinnaird/Getty Images)