Caroline Wozniacki, formerly the top-ranked player in the world, will play the 2020 Australian Open as her final tournament, she told ABC's "Good Morning America" on Friday.

Wozniacki, the 2018 Australian Open winner, also announced her decision in a post on Instagram.

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I've played professionally since I was 15 years old. In that time I've experienced an amazing first chapter of my life. With 30 WTA singles titles, a world #1 ranking for 71 weeks, a WTA Finals victory, 3 Olympics, including carrying the flag for my native Denmark, and winning the 2018 Australian Open Grand slam championship, I've accomplished everything I could ever dream of on the court. I've always told myself, when the time comes, that there are things away from tennis that I want to do more, then it's time to be done. In recent months, I've realized that there is a lot more in life that I'd like to accomplish off the court. Getting married to David was one of those goals and starting a family with him while continuing to travel the world and helping raise awareness about rheumatoid arthritis (project upcoming) are all passions of mine moving forward. So with that, today I am announcing that I will be retiring from professional tennis after the Australian Open in January. This has nothing to do with my health and this isn't a goodbye, I look forward to sharing my exciting journey ahead with all of you! Finally, I want to thank with all my heart, the fans, my friends, my sponsors, my team, especially my father as my coach, my husband, and my family for decades of support! Without all of you I could have never have done this!

A post shared by Caroline Wozniacki (@carowozniacki) on Dec 6, 2019 at 5:31am PST

Wozniacki, 29, battled injuries in 2019, playing only 35 matches. It was the first year since 2007 that the Danish star failed to win a singles title. She lost in the round of 32 in three majors and the first round of the French Open last season.

In 2018, she was diagnosed with rheumatoid arthritis and battled autoimmune disease prior to the US Open. She had slipped to 37th in the latest world rankings after finishing 2018 in the top five for the fifth time in her career.

Wozniacki married former NBA All-Star David Lee in June. She last played in the China Open in October, losing in the semifinals to Naomi Osaka in straight sets.

Wozniacki turned professional in 2005 and won 630 career singles matches and 30 career titles. She was the world No. 1 in 2010 and 2011. She earned more than $35 million in career prize money during her career.