Williams was bounced from the women's singles draw on Day 1 at Melbourne Park, but was eyeing a fifth Aussie Open doubles title alongside younger sister Serena. The dominant duo had been absent from the doubles competition over the previous two years, but returned to the draw in 2014.
It remains to be seen how severe Williams' injury is and how long it could sideline her. However, at age 33, you have to wonder how much the seven-time Grand Slam singles champion has left in the tank.
After all, Williams hasn't been past the fourth round at a major tournament since 2010 and revealed that she was diagnosed with Sjogren's syndrome in 2011, an autoimmune disorder that results in fatigue and muscle pain.
Williams is currently the 37th-ranked player on the WTA tour.