Sam Horsfield is the latest golfer to have been ruled out of this week's US Open after testing positive for Covid-19.
The 24-year-old Englishman tested negative in a pre-arrival test taken last week but then tested positive after arriving in New York for the tournament.
"Sam has had an excellent year on the European Tour, winning the UK series to earn a spot in this year’s US Open at Winged Foot, and we are disappointed to lose a player of his calibre from the field," said USGA senior managing director John Bodenhamer.
"It goes without saying that I am hugely disappointed to not have the opportunity to play in my fourth U.S. Open but clearly the safety of the tournament and other players is paramount," Horsfield, who competed in the 2015, 2016 and 2019 editions, wrote on Twitter.
The USGA announced earlier on Monday that American Scottie Scheffler, 24, had also withdrawn after testing positive.
Horsfield and Scheffler, who are both asymptomatic, have been replaced in the field by Rory Sabbatini and Branden Grace respectively.
Grace missed last month's US PGA after his own positive coronavirus test, which had forced him to pull out of the Barracuda Championship while tied second at the halfway stage.
The 120th US Open will be held at Winged Foot Golf Club, in Mamaroneck, New York.