Serena Williams may be in line for an extended break to finish the year.
Williams' coach, Patrick Mouratoglou, said Tuesday the world No. 1 could use more rest after the U.S. Open, where her bid for a Grand Slam came to an end with a semifinals loss to unranked Roberta Vinci.
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As a result, Williams, 34, may remain sidelined through the rest of 2015.
"I don't doubt she will have the motivation to win more (major tournaments) and reach records," he told ESPN. "I'm just thinking about the end of the season, and I don't know how high the motivation is, and I don't think she should go play competitions if her motivation is not high enough."
Williams has enjoyed an incredible year. She won the season's first three majors and holds a 53-3 win-loss record. Still, Mouratoglou said the loss at Flushing Meadows had a huge impact on Williams.
"She was two matches away from something really big, so it was very painful," he said. "Any loss is very painful for her, but this one even more than usual, so it just takes time to recover from it.
"When the motivation comes back, which I don't doubt it will, then it will be time to start tournaments again."