"Serena Williams, out of action since winning Wimbledon in July, has experienced another significant health problem that could further delay her return to the game she once dominated. Williams’s representatives confirmed Wednesday that she was hospitalized last month in Los Angeles because of a pulmonary embolism and that she then required emergency treatment Monday for a hematoma, a pocket of blood that swells under the skin.

A pulmonary embolism — a clot that blocks blood flow to the lungs — can be life threatening in severe cases, but Williams’s spokeswoman, Nicole Chabat, said in a statement Wednesday that “thankfully everything was caught in time” and that Williams was resting and recovering at her home in Los Angeles.

“This has been extremely hard, scary, and disappointing,” Williams said in a statement. “I am doing better. I’m at home now and working with my doctors to keep everything under control. I know I will be O.K., but am praying and hoping this will all be behind me soon. While I can’t make any promises now on my return, I hope to be back by early summer. That said, my main goal is to make sure I get there safely.“

Read More: NY Times