It's the elbow injury heard 'round the tennis world.

World's No. 1 Serena Williams pulled out of the Italian Open on Thursday, citing a damaged right elbow as the culprit before her third-round match against Christina McHale.

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"It wasn't an easy decision," she said, according to The Guardian. "I talked with my coach and he was like: 'It wouldn't be very smart for you to play.' I said: 'I hate quitting,' and he said: 'This is not about quitting, this is about making the best decision.'"

Williams' comments sounded as if her withdrawal was a precaution as she prepared for the start of the French Open on May 25.

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"It's smart that I learned from things in the past," Williams said, referring to previous withdrawals ahead of slams. "If I continue to play, it can really hurt my chances, not only for Roland Garros but maybe also for Wimbledon."

She added that her elbow began hurting in Madrid last week.

"I wasn't serving my best," Williams said. "When you're injured you don't have that much confidence."

According to the Sydney Morning Herald, Serena acknowledged that playing hurt affects her mental approach.

"I wasn't hitting my shots the way I wanted to," she said. "When you're injured you don't play with much confidence. It's so important to have that when you're going up against any player."

Which begs the question: Why did Williams try to play in Rome at all? Williams had not lost a match all season until her semifinal loss at Madrid against Petra Kvitova.

Williams won her opening match in Rome, a 6-1, 6-3 straight-set sweep over Anastasia Pavlyuchenkova. She may have thought the layoff between her loss in Madrid and the start of the French Open was too long without playing a competitive match, but she wasn't saying.