Maybe Serena Williams should have been focusing on her own career, rather than trying to help Caroline Wozniacki resume hers.

Serena Williams refuses to criticize Wimbledon's Centre Court snub

The world's No. 1 player failed to reach the quarterfinals of a Grand Slam tournament for the fifth straight time, losing to 25th-seeded Alize Cornet 1-6, 6-3, 6-3 in the third round at Wimbledon on Saturday.

After Williams lost in the second round of the French Open last month to Garbine Muguruza, she met up with Wozniacki, who had just suffered a public breakup with fiancé Rory McIlroy. The two partied in Miami - as Serena helped Wozniacki move on from her failed relationship.

But does Williams need help with her own failed relationship? Sports World News was among the outlets to report in February that Williams hinted that she had broken off her romantic relationship with her coach/boyfriend Patrick Mouratoglou.

Serena Williams breaks off romantic relationship with coach Patrick Mouratoglou.

In February, Williams posted a strange tweet, saying, "Me. Mine. Alone. Myself. I. One. Solo. Unaccompanied."

It had been suggested that Serena's time with Wozniacki was an opportunity for her to get her mind off her relationship with Mouratoglou. The part that doesn't add up is that if the two were linked romantically and then stopped, why would Serena still use him as coach?

But something is wrong, as Mouratoglou himself pointed out. Someone of Cornet's prowess does not beat Serena twice in a year (she beat Williams earlier in Dubai).

"The fact that there is zero reaction is a very big indicator that she's not there at all," Mouratoglou said, according to USA TODAY Sports. "She's pushing the ball, expecting mistakes. She's not going to win like this, I know.

"Definitely since January she is not there. She's not herself. She's an average player if she doesn't have the mindset that she usually has on the court."

Williams raised the bar last year with 11 victories, so it's not out of the realm of possibility to assume that she wasn't going to match last year's performance.

She has been getting opponents' best for years, so for her to say, "I think everyone in general plays the match of their lives against me, as if they're on the ATP Tour," seems like an excuse.

Maybe it's time for Wozniacki to take Serena some place to clear her head.

What do you think is wrong with Serena Williams? Comment below or tell us @SportsWN.