Golf's world No 1 Jon Rahm withdrew from the Tokyo Olympics on Sunday after testing positive for Covid-19 for the second time in two months, the Spanish Olympic Committee confirmed.
Rahm, who stormed to victory at the US Open in June, returned a positive sample after undergoing mandatory testing following his recent participation in The Open at Royal St George's.
It was the latest twist to what has been a tumultuous season for the 26-year-old Spaniard.
In June, he was forced to withdraw from the PGA Tour's Memorial Tournament while defending a six-shot lead heading into the final round after returning a positive test.
Rahm later revealed he had been vaccinated shortly before contracting the disease.
He then bounced back from that setback to clinch a stunning victory at the US Open at Torrey Pines a fortnight later, taking the championship with back-to-back birdies on the final two holes.
Rahm's withdrawal from the Games came shortly after American golfer Bryson DeChambeau was also forced to pull out following his own positive Covid-19 result.
It means Olympic golf will be without the last two US Open champions, with DeChambeau winning the tournament in 2020 at Winged Foot.
Spain's golf medal hopes have been significantly impacted by Rahm's withdrawal, with the team's remaining representative being the world No 166 Adri Arnaus as there was no time to call up a replacement.
The United States, meanwhile, should be able to cope in the absence of DeChambeau at Kasumigaseki Country Club, where Open champion Collin Morikawa, world No 4 Justin Thomas, fifth-ranked Xander Schauffele, and former Masters champion Patrick Reed - who was called up to replace DeChambeau - make up a fearsome team.
The first round of the men's Olympic golf tournament begins on Thursday and will be played over four rounds of stroke play. The women's tournament is then scheduled to start on August 4.