Wednesday brought news that shocked tennis fans around the world: Venus Williams, a seven-time major champion, has withdrawn from the U.S. Open.

Williams revealed she was recently diagnosed with Sjogren's Syndrome, an autoimmune disorder that affects one’s energy level and causes fatigue and joint pain, the tennis star said in a statement.

The 31-year-old had pulled out of two other tournaments earlier this summer because she was not feeling well.

On Monday, in her first match in two months, Williams made a triumphant return to the court when she beat Vesna Dolonts 6-4, 6-3 at Flushing Meadows.

Williams was poised to play the 22nd-seeded Sabine Lisicki in the second round.

Now that Williams is out, the women’s field will be even more uncertain.