Kansas City Chiefs guard Laurent Duvernay-Tardif became the first NFL player to opt out of the 2020 season due to the coronavirus pandemic.
Duvernay-Tardif, the only active NFL player with a medical doctorate, announced his decision on Twitter on Friday.
In a statement, the 29-year-old said he was unwilling to put people at risk by playing this season.
"Given the worldwide sanitary crisis we are currently experiencing, the NFL and the NFLPA have agreed to significant health and safety protocols to protect the players. There is no doubt in my mind the Chiefs' medial staff have put together a strong plan to minimise the health risks associated with COVID-19 but some risks will remain," he wrote.
"This is one of the most difficult decisions I have had to make in my life but I must follow my convictions and do what I believe is right for me personally. That is why I have decided to take the Opt Out Option negotiated by the league and the NFLPA and officially opt out of the 2020 NFL season.
"Being at the frontline during this offseason has given me a different perspective on this pandemic and the stress it puts on individuals and our healthcare system. I cannot allow myself to potentially transmit the virus in our communities simply to play the sport that I love. If I am to take risks, I will do it caring for patients.
"I want to thank everyone in the Kansas City Chiefs organisation for their support and understanding."
Duvernay-Tardif helped the Chiefs win Super Bowl LIV earlier this year.
They are scheduled to begin their regular season against the Houston Texans on September 10.