"After testing positive for COVID-19 on June 8, my battle with it has been complicated and arduous," the 23-year-old wrote. "As I continue to fight to fully recover, I had to make the difficult decision on a deadline to opt out as a medical high-risk player.
"So much about the virus is unknown and my heart is heavy, even as I make the decision that I know is best for my long-term wellness."
The decision delays Durr's on-court debut alongside Oregon phenom Sabrina Ionescu, who was selected first overall in this year's draft.
"While we are disappointed that we will need to wait a bit longer to see (Durr) emerge as one of the bright young players in the game, we fully recognize and support the difficult decision she had to make amidst unprecedented circumstances," Liberty general manager Jonathan Kolb said in a statement. "Brooklyn will be ready for her in 2021."