Venus plans to return in February

Venus Williams' injury woes continue (GETTY IMAGES)

Venus Williams has withdrawn from the Australian Open, prolonging her absence from the tennis tour because of an autoimmune disease that can cause fatigue and joint pain.

The seven-time Grand Slam title winner announced via Twitter and on her website that she wouldn't play in the year's first major tournament, which starts on Monday. She added, though, that she plans to be back in action next month.

Williams hasn't played competitively since 29 August at the US Open. Two days later, she pulled out of that tournament, revealing that she'd been diagnosed with Sjogren's syndrome.