The world number seven said she will now miss the rest of the season.
“As hard as it was to come to this conclusion, I have so much to look forward to in 2021, including the Olympics,” said the Canadian.
“I want to use this time to focus on my game so I can come back stronger and better than ever.”
Andreescu said she will be able to focus on her “health and training” for the remainder of 2020.
After winning her first Grand Slam at Flushing Meadows in 2019, Andreescu missed the Australian Open early this year with the knee injury and, after Wimbledon was postponed, she also withdrew from this month’s US Open.