World number one Serena Williams announced her withdrawal from the Madrid Open due to flu on Friday, 24 hours before the WTA Premier Mandatory tournament begins.
Williams has featured in only two events since her defeat to Angelique Kerber in January's Australian Open final, finishing as the runner-up in Indian Wells prior to a shock last-16 loss at the hands of Svetlana Kuznetsova at the Miami Open.
And the 34-year-old will now have limited clay-court preparation ahead of the French Open, which starts on May 22, after revealing she will be unable to challenge for a third title in Spain's capital.
"Unfortunately, I have to withdraw from Madrid because I've been battling the flu and I'm not at 100 per cent. I look forward to returning soon," said Williams.
In Williams' absence, Agnieszka Radwanska - a beaten semi-finalist in four of her last five outings - will now be the highest-ranked player in Madrid.
CAN AZARENKA CONTINUE TO SHINE ON CLAY?
Victoria Azarenka is unquestionably the form player on the WTA Tour, successive wins in Indian Wells and Miami taking her tally of titles in 2016 to three. The Belarusian now faces the challenge of replicating her supreme hard-court performances on clay - and can take heart from two previous runs to the final of the Madrid Open, in 2011 and 2012.
RADWANSKA WITH POINT TO PROVE
Radwanska kicked off 2016 by claiming victory in Shenzhen, but a recent flurry of last-four exits is likely to have frustrated the classy Pole. The most recent of Radwanska's semi-final losses came in Stuttgart last week against qualifier Laura Siegemund and the world number two will be eager to bounce back by capitalising on Williams' withdrawal.
TOP HALF LOOKING TOUGH
Radwanska, Azarenka and defending champion Petra Kvitova are all in the top half of the draw, which would appear the trickier section to navigate. There is also a tough opening tie in prospect for Radwanska against world number 38 Dominika Cibulkova, who almost triumphed when the duo met in Indian Wells last month. Kerber and home favourite Garbine Muguruza represent the leading names in the bottom half of the draw.
KVITOVA A CLASS APART IN 2015
Kvitova needed three sets to win her first- and second-round matches in Madrid 12 months ago, but was in top form by the latter stages of the tournament. After ending Williams' 27-match unbeaten run in the semi-finals with a 6-2 6-3 victory, Kvitova dropped just three games against Svetlana Kuznetsova en route to a second title at this event.
BEST OF BOTH WORLDS FOR AZARENKA
Perhaps unsurprisingly given her success this year, Azarenka leads the WTA Tour in two key statistics. Her 24-1 record in 2016 owes much to the fact she has held in 82.4 per cent of her service games, while also winning 54.3 per cent of return games.
CONDITIONS IDEAL FOR DEFENDING CHAMP
Kvitova is unsurprisingly confident ahead of her title defence. The Czech was quoted by the Madrid Open's official website as saying: "I love the conditions over there, definitely, with the altitude and as the balls are flying so heavy. With my aggressive game this really pays off. I think this really helps and the clay is very good for me as well, so I think that everything you find there really helps me."