Hideki Matsuyama and his team were robbed during a stopover in London while heading to the first leg of the PGA Tour playoffs after winning a bronze medal at the Paris Olympics, Japanese media reported on Wednesday.
The former Masters champion told Golf Digest Japan that he had his wallet stolen and the passports and visas of his caddie Shota Hayato and coach Mikihito Kuromiya were also taken.
The world No. 12 Matsuyama told the website that Hayato and Kuromiya have returned to Japan and are working to get their documents reissued.
The earliest they will be able to travel to the United States will be for the Aug. 29-Sept. 1 season-ending Tour Championship.
"There's a chance they'll make it, but we have to go into it thinking it's close to zero," Matsuyama told Golf Digest.
Representatives for Matsuyama and the PGA Tour did not immediately respond when asked to confirm reports of the robbery.
Matsuyama secured Japan's first Olympic medal in men's golf in Paris.
Videos online showed Matsuyama warming up at TPC Southwind in Memphis, where he was scheduled to play the opening two rounds on Thursday and Friday.
The top 50 finishers move on to the Aug. 22-25 BMW Championship in Castle Rock, Colorado, from where the top 30 go on to the Tour Championship at East Lake Golf Club in Atlanta.