Four-time Olympic gold medalist Serena Williams will not pursue a fifth at the Tokyo Olympic Games.

Williams, who last won a singles gold medal at the 2012 London Games, declined on Sunday to say exactly why she opted not to play. That said, she did say she had a variety of reasons for her decision.

“There’s a lot of reasons that I made my Olympic decision,” Williams told reporters at Wimbledon. “I don’t really want to — I don’t feel like going into them today. Maybe another day. Sorry.

“I have not thought about it. In the past (the Olympics) has been a wonderful place for me. I really haven’t thought about it, so I’m going to keep not thinking about it.”

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Williams, 39, also won doubles gold medals in Sydney in 2000, Beijing in 2008 and London in 2012 alongside sister Venus Williams. She participated in the 2016 Olympics in Rio de Janeiro, suffering upsets in both singles and doubles play to interrupt her previously unbeaten Olympic career.

“Ultimately, the decision to participate in the Games is an individual one, and as we emerge from the pandemic, we recognize and respect the personal decisions made by our top athletes regarding participation in the Tokyo Games,” U.S. Tennis Association spokesman Chris Widmaier told the Associated Press. “Although we fully support the IOC and the (International Tennis Federation), and have encouraged our athletes to participate, we recognize the fact that in this unique time, some athletes may choose not to participate for personal reasons.”

Williams will next play at Wimbledon as the tournament’s sixth seed in her bid to tie Margaret Court’s record of 24 Grand Slam singles titles.