10 questions for Serena Williams

Serena Williams returns to the court next week at the Bank of the West Classic for the first time since defaulting out of the Wimbledon doubles. Steve Bardens/Getty Images

Last time we saw Serena Williams, in the second round of the women's doubles at Wimbledon, she looked as if she had just taken a ride on the Tilt-A-Whirl. The weaving and wobbling from the No. 1 player in the world was both baffling and frightening.

Williams, who blamed the incident on a "viral illness," will play on Wednesday night for the first time since pulling out of that Wimbledon match on July 1. "I am heartbroken I'm not able to continue in the tournament ..." Serena said in a statement after the match. "But this bug just got the best of me."

Here are 10 questions we'd like answered before she takes the court at the Bank of the West Classic at Stanford University.

1. What, exactly, happened at Wimbledon?

The No. 1 player in the world and the owner of 17 major titles could scarcely bounce and catch the ball, let alone get her serve over the net. She whiffed, she wavered, she double-faulted on all four of her service points before defaulting while trailing 3-0. So what caused that? And please don't stop at "viral illness."

2. Did the symptoms come on suddenly?

Many people have wondered how Williams made it onto the court in the first place. Where was her support system? Why didn't her doubles partner and sister, Venus, step up? And why, after she made her way onto the court and was obviously not right during warm-ups, did she even attempt to play?

3. Had Serena taken any medication for her illness before taking the court?

Look no further than your own medicine cabinet and you'll probably find bottles with warning labels that contain words like "dizziness" and "drowsiness." An adverse reaction to medication is certainly one plausible explanation for Serena's inability to play.

4. Was Serena drug-tested after the match? If so, what were the results?

The International Tennis Federation is in charge of drug testing at Grand Slam tournaments. The organization will not discuss specific cases but does say that "samples are collected on both a random and targeted basis. There is no rule which specifies when a player may [or may not] be tested."

5. What did Venus say to Serena after the match?

It was hard to read Venus' reaction as Serena was bouncing serves into the net and floating them well beyond the service box, but it must have been both scary and frustrating for her, as well. The best chance for Venus to add to her Grand Slam haul is with Serena in doubles, so it had to be a bummer to see another chance come and go.

6. Was Serena feeling ill during her third-round singles loss to Alize Cornet?

The woman known for her fierce competitiveness looked tentative during her 1-6, 6-3, 6-4 loss to the No. 25 player in the world, and her shots seemed to lack the bite they normally deliver. She admitted afterward to not really knowing what happened after coming into the tournament feeling well prepared. "Right now, I don't really know what I did wrong," she said after the match. "Usually, I do."

7. What's going on with Serena and coach Patrick Mouratoglou?

Mouratoglou said at Wimbledon that he hadn't seen Serena in the two days prior to the doubles debacle. Last week he told France's Tennis Magazine that despite rumors to the contrary, they were still working together but that Serena was going through "a difficult period."

8. Was there an emotional component to what happened at Wimbledon?

After the doubles loss, Williams' sister Isha Price told USA Today that Serena had been feeling "sad" and "emotional" since her loss to Cornet. We know she's a sensitive person. You wonder how much that early Wimbledon exit, on top of losing in the fourth round of the Australian and second round of the French, played into it.

9. Is Father Time playing a role?

Williams has always been able to bounce back from low points and restore her confidence. But what will it take this time? Serena turns 33 on Sept. 26, and she hasn't advanced past the fourth round of a Grand Slam this year. After losing in the second round of the Family Circle Cup in April, she said she was flat-out spent. "I'm really just dead," she said. "I need some weeks off where I don't think about tennis and kind of regroup." Since Wimbledon, Serena has posted photos online of herself vacationing in Croatia. May she did just really need a vacation.

10. How big a part does Serena's pride play in all of this?

Serena has been ranked No. 1 now for 74 straight weeks, the longest streak since Martina Hingis held the top spot for 80 weeks in 1997 and '98. Serena still has a pretty significant lead (2,271 points) over No. 2 Li Na, but she also has a lot of points to defend, having won the US Open a year ago. You wonder how long she would continue if she was playing decently but not winning Slams, or even losing her No. 1 ranking.