This is why Serena Williams needs to be more open with the media.

The world's top-ranked player, who on Sunday earned her first win on the court since the U.S. Open quarterfinals, refuted comments from her coach and rumored former boyfriend Patrick Mouratoglou that she lacked the motivation to continue playing in 2015 after her shocking U.S. Open semifinals loss to Roberta Vinci, according to Radio New Zealand.

Serena Williams Coach, Patrick Mouratoglou, Blames U.S. Open Loss On Knee Injury

After Vinci ended Serena's dreams of a calendar Grand Slam, she withdrew from tournaments in China and the WTA Finals. Mouratoglou initially indicated that she was too emotionally drained to compete following her heartbreaking loss in New York.

"When she lost in Toronto [in August], she was very disappointed, but we went back to practice the morning after because she wanted to win the U.S. Open," Mouratoglou said in a phone interview with espnW from France. "But after this year and the three Grand Slams [she won in 2015], the question is how high her motivation is to play those tournaments. I don't think she should play if the motivation is not really high."

Serena Williams Has No Motivation To Finish 2015, Coach Says

Williams, however, said that's not really the case.

"I never lacked motivation. I just was really injured," she told reporters in Manila, without discussing the nature of the injury, Radio New Zealand reported. "I've always been motivated, so I just had to get better -- you know, be able to just walk without being in pain."

Mouatoglou did say two months after the U.S. Open that Williams' knee injury was a factor in her loss to Vinci.

Williams, who had lost an exhibition to Caroline Wozniacki and her first International Professional Premier Tennis match against Karolina Pliskova in her only competitive matches since losing to Vinci, bounced back with a 6-3 win over Ana Ivanovic.

"It was good to be back here," Williams said, representing the Philippine Mavericks team against Ivanovic's UAE Royals. "It's a good opportunity for me to get some more tennis in and get ready. I felt really good."

Williams begins her 2016 season at the Hopman Cup in Perth on Jan. 3.

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