As her coach hinted earlier this week, Serena Williams has withdrawn from the last two tournaments of the 2015 WTA season.

There were no hints, however, that Williams would cite her physical health as the primary reason her withdrawal.

U.S. Open Defeat Saps Motivation For Serena Williams To Finish 2015 Season

The 21-time Grand Slam champion is drawing criticism for her announcement that she will skip the China Open and the season-ending WTA Finals. Her coach Patrick Mouratoglou had said he didn't think she was motivated to finish the season.

"It's no secret I've played injured most of the year -- whether it was my elbow, my knee, or, in the final moments after a certain match in Flushing, my heart," Williams said, according to USA Today Sports' For the Win.

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"I'm a fierce competitor. And I want to compete as well as I can, for as long as I can. So I am taking a proactive step and withdrawing from tournaments in Beijing and Singapore to properly address my health and take the time to heal."

Williams does earn points for poking fun at herself with the comment about her heart, but to talk about any other injuries before that hints that she was suggesting she wasn't 100 percent during her U.S. Open semifinals loss to Roberta Vinci.

The injury excuse rankled For the Win: "It's no secret she's played injured most of the year? Oh come on. First of all, most people reading this statement (e.g., non-tennis fans) don't know this and even the tennis fans are rolling their eyes. Everybody plays hurt. Let's not make it like you were going down into the coal mines every day with broken limbs."

Not to mention the fact that if Williams is as fierce a competitor as she claims, wouldn't she want to erase her shocking defeat in the U.S. Open semis that prevented her from winning the calendar Grand Slam? Taking such a long break at Serena's ripe old age of 34 could affect her legacy, ESPN added.

"It's tougher for an older player to get fit, and no amount of practice or exhibition play is a substitute for actual match play," ESPN's Peter Bodo speculated. "Incidentally, (Roger) Federer is acutely aware of that, which is why he plays such a balanced schedule. He takes long periods off, but he plays right into the late fall.

A significant break could certainly help Williams recover and recharge. On the other hand, it's also a serious break of continuity -- roughly four months between the last ball she hit at the U.S. Open and the next one she hits at a major."

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