But even the American 23-times Grand Slam champion, back after having her first child in September, must have been bewildered when a USA reporter tried to throw a new light on her fierce rivalry with old foe Maria Sharapova, who she faces in the French Open last 16 on Monday.
She first felt a problem with her right pectoral muscle in her third-round match against Julia Gorges last Saturday and revealed yesterday that she could not serve.
Williams admitted she now faces a race against time in order to be fit for the grass court season and Wimbledon.
She was also in just her third tournament of the year after giving birth to daughter Olympia in September.
"I'm beyond disappointed. I gave up so much and gave everything on the court, all for this moment", Williams told a hastily-arranged news conference.
Sharapova had a 2-19 record against Williams. "The first time I felt it was against Görges in my last match".
"It's very hard", Williams added.
Andre Iguodala to miss Game 1 of NBA Finals with leg contusion
In his eighth straight NBA Finals, he probably needs to produce numbers like that in every game to give the Cavaliers any chance. The Golden State Warriors and the Cleveland Cavaliers will meet in the NBA Finals for the fourth straight season.
However, the 23-time Grand Slam victor will now have to focus on making a recovery in time for the start of the grass-court season. "And try to get better and not get it to a point where it could be a lot worse".
Williams: "I honestly don't have any thoughts about that. It all depends and Serena will have to decide for herself what she has to do when she goes to Wimbledon". It didn't really get a lot better'.
News of her pullout comes after the editor of a tennis magazine was criticised for asking Williams if she was intimidated by her rival's appearance.
She'll get an MRI on Tuesday.
The German, a former World No 1 and a two-time major victor, reached the quarter-finals for the second time with a 6-2, 6-3 win over France's Caroline Garcia.
She will face either 2016 champion Garbine Muguruza or Lesia Tsurenko of Ukraine for a semi-final place. I've made every sacrifice I could. That's when I started to feel it. Just her game matches so well against mine.
Venus Williams (USA) and Serena Williams (USA) during their doubles match against Andreja Klepac (SLO) and Maria Jose Martinez Sanchez (ESP) (not pictured) on day eight of the 2018 French Open at Roland Garros.