The former world champion's withdrawal gifts Sharapova a quarter-final berth where she will face either Garbine Muguruza or Lesia Tsurenko.
Sharapova released her book in September 2017 where she had written that Serena "hated" her because she had heard her cry after 2004 Wimbledon final.
"I'm beyond disappointed. You know, I gave up so much, from time with my daughter to time with my family". And while she's "pretty much had every injury in the book", this was the first time dealing with this particular malady.
"I have given up so much to be here".
"I enjoyed the court and I think I've played my best match so far here". "I just started. So I'm just really trying to get my bearings and trying to feel out where I am and see where I can go", Serena stated.
Next up will be a meeting with either her long-time nemesis Serena Williams, who has beaten Sharapova in 18 successive encounters dating back to 2005, or Germany's Julia Goerges.
"I love playing Maria - it's just a match I always get up for". So it's extremely disappointing.
PSerena Williams reportedly hurt her arm while playing in a doubles match with sister Venus. I put everything on the court, all for this moment.
"Every match has been getting better for me".
"Right now, I can't actually serve so it's actually hard to play when I can't physically serve".
The Romanian has developed a reputation as a choker after losing three grand slam finals, including two in Paris, but looked anything but nervous against her 22-year old opponent.
"But also, I made a promise to myself and to my coach and to my team that if I'm not at least 60 per cent or 50 per cent, then I probably shouldn't play. I think it's these kind of new situations that she'll go home and learn a lot about how she is feeling", Clijsters added.
"I tried a lot of different tapings and support and it didn't really get a lot better", the American added. "So it's just, like, I think it would be more shocking if I wasn't in tears", she said. "I wish her a speedy recovery and hope she returns to the tour soon".