Serena Williams showed frustration throughout the beginning of her first match at the Australian Open, leaving many fans wondering if they were possibly signs of a possible retirement.

Despite winning the match, the 32-year-old American tennis star encountered her most glaring error in the sixth game of the second set when a looping backhand from Petkovic landed just over the net to set up an easy winner but Serena Williams was fooled by prodigious backspin and wildly missed the ball with a forehand, EuroSport.com reports.

Serena Williams' coach and rumored boyfriend Patrick Mouratoglou mentioned during a September interview that the American tennis star and Victoria Azarenka are "competing at the highest level," leaving many fans wondering if he predicted a rivalry during the Australian Open.

"Of course they have a good relationship, but it's difficult to have real friends," Mouratoglou said, according to ESPN.

"So, they're not real friends, but they appreciate each other, they're joking; they are friends, but as much as they can be because they're competing at the highest level."

Victoria Azarenka thinks her rivalry with Serena Williams is making her a better player and is looking forward to renewing it over the next four weeks at the Brisbane International and the Australian Open, DNAIndia.com writes.

But the upcoming tournament isn't the only thing Serena Williams' fans are talking about.

Serena Williams used the hashtag "#solo4life" in a recent Twitter post where she described a day spent to herself, leaving many fans wondering if she has ended her romantic relationship with rumored boyfriend and coach Patrick Mouratoglou.

"I have been having some quality time with myself today," she wrote in her post.

"Movies with myself and driving around with myself. I think I like me."