Johnson, 32, is the father of an 18-month-old son, Tatum, with fiancée Paulina Gretzky, daughter of hockey great Wayne Gretzky. The couple plan to expand their family.
“This was not an easy decision for me, but my concerns about the Zika virus cannot be ignored,” the U.S. Open champion said in a statement, according to ESPN. “Paulina and I plan to have more children in the near future and I feel it would be irresponsible to put myself, her or our family at risk. I believe I am making the right decision for me and most importantly my family.”
The Zika virus, which is linked to the microcephaly birth defect, can lead to a number of different conditions in babies, including premature birth and blindness.
Related Video: VIDEO: Florida Mom Suspects Zika Virus Caused Her 18-Year-Old Son’s Debilitating Birth Defect
The number two-ranked golfer in the world is the 13th golfer to pull out of the Olympic Games due to concerns of the Zika virus. He joins world number one Jason Day of Australia, fourth-ranked Rory McIlroy of Ireland and world number eight Adam Scott of Australia in opting to skip Rio, despite golf’s return to the Olympics for the first time in 112 years.
For more of PEOPLE’s Olympic coverage, pick up our collector’s edition, The Best of the Games, on sale now
Although Johnson is the first American golfer to announce his withdrawal, third-ranked Jordan Spieth has previously said he was “uncertain” about going to the Olympics.
In June, American cyclist Tejay van Garderen became the first U.S. athlete to withdraw his name from Olympic consideration due to concerns about the virus and the potential effects it could have on his pregnant wife.
Basketball stars Steph Curry and LeBron James also dropped out of consideration for Team USA, although they claimed it was to recover from their basketball season and not because of Zika.
