Karl-Anthony Towns announced Friday that he has tested positive for the coronavirus, nine months after losing his mother, Jacqueline, to covid-19.

The two-time all-star center issued a statement on Twitter confirming his diagnosis, which came amid a rise in positive tests and postponed games across the NBA this week. The Timberwolves were scheduled to host the Memphis Grizzlies on Friday, but the game was postponed because Minnesota didn’t have enough available players because of the NBA’s contact tracing rules. Teams must have eight active players to take the court.

“Prior to tonight’s game, I received yet another awful call that I tested positive for COVID,” Towns wrote. “I will immediately isolate and follow every protocol. I pray every day that this nightmare of a virus will subside and I beg everyone to continue to take it seriously by taking all of the necessary precautions.”

Towns revealed in an emotional video in March that his mother was in a coma and had to be placed on a ventilator after contracting the virus. Jacqueline Towns, a native of the Dominican Republic who had been a fixture at her son’s games as he went from a five-star high school recruit to a one-and-done season at the University of Kentucky to the top draft pick in the 2015 NBA draft, died April 13. Towns referred to his mother as “the strongest woman I know.”

“We cannot stop the spread of this virus alone, it must be a group effort by all of us,” Towns said in his statement Friday. “It breaks my heart that my family, and particularly my father and sister, continue to suffer from the anxiety that comes along with this diagnosis as we know all too well what the end result could be. To my niece and nephew, Jolani and Max, I promise you I will not end up in a box next to grandma and I will beat this.”

Towns returned to the court in December with a heavy heart, telling reporters that his “soul has been killed off” following his mother’s death and adding that he had lost at least six other family members to covid-19.

“I only know what happened from April 13 on,” Towns said in December. “Because you may see me smiling and stuff, but that Karl died on April 13. He’s never coming back. I don’t remember that man. I don’t know that man.”

The 25-year-old center is averaging 22 points, 12.5 rebounds and 4.3 assists this season, although he has only played four games because of a wrist injury.

Towns is one of several stars to be sidelined in recent weeks because of a positive coronavirus test or contact tracing, including Kevin Durant, Bradley Beal and Jayson Tatum. The NBA has had to postpone at least 12 games this week because of positive tests and contact tracing.

Nevertheless, the NBA has said it plans to continue the season. Commissioner Adam Silver hasn’t established clear criteria for what would need to happen for the NBA to put all of its games on hold. The league released its 2020-21 schedule in two parts to allow flexibility to make up postponed games if necessary.

“If we found a situation where our protocols weren’t working, meaning that not only did we have some cases of covid but that we were witnessing spread either among teams or even possibly to another team, that would cause us to suspend the season,” Silver said in December. “I think we are prepared for isolated cases. In fact, based on what we’ve seen in the preseason, based on watching other leagues operating outside the bubble, unfortunately it seems somewhat inevitable. But we’re prepared for all contingencies.”