U.S. Open champion Bianca Andreescu has withdrawn from the ABS Classic due to a lingering left knee injury.

Andreescu said in a video released Tuesday on social media by tournament organizers that she was disappointed with the decision but that she needed more time to recover from the injury she sustained during the WTA Finals in late October at Shenzhen, China.

She was forced to retire from her second round-robin match against Karolina Pliskova.

“I spoke to my team and I really have to do what's best for my knee right now. I have so many amazing memories (in Auckland), so hopefully I can make more in 2021," the 19-year-old Canadian said in the video.

Andreescu began an outstanding 2019 season with a runner-up finish in Auckland, beating former world No.1s Caroline Wozniacki and Venus Williams before losing in the final to Julia Georges.

She later won three titles, including her first Grand Slam singles title at the U.S. Open.

Andreescu has entered the Australian Open beginning Jan. 20 in Melbourne.