Serena Williams got a little emotional when asked about possible retirement following her 6-3, 6-4, loss against Naomi Osaka in the Australian Open semifinal, HuffPost reported

"I don't know," the 39-year-old said when reporters asked her about the mistakes she made during the match. "I'm done."  

Williams then exited the press conference. 

The rumors of retirement intensified when Williams waved to the crowd and put her hand over her heart as she exited the court after the loss. 

“If I ever say farewell, I wouldn’t tell anyone,” the tennis star said when asked about the gesture during the press conference. 

"Today was not an ideal outcome,” Williams wrote on Instagram

"I am so honored to be able to play in front of you all," she told her fans in Melbourne, Australia. "Your support — your cheers, I only wish I could have done better for you today. I am forever in debt and grateful to each and every single one of you. I love you. I love you. I love you. I adore you."

Williams had a chance to earn a record-tying 24th Grand Slam singles title. But Osaka spoiled the opportunity, reaching her fourth major title match and stretching her winning streak to 20 matches, ESPN reported

"I don't know if there's any little kids out here today, but I was a little kid watching her play," the 23-year-old said about Williams. "And just to be on the court playing against her, for me, is a dream."

Williams has won seven titles in Melbourne, according to ESPN. Her most recent title came in 2017 when she was pregnant with her daughter, Olympia. 

Williams was visibly frustrated during her loss on Thursday, where she was heard screaming, “Make a shot! Make a shot!"

Osaka advances to the championship, where she will face 22nd-seeded American Jennifer Brady. The young star, who was raised in the U.S., will take part in her fourth major final as she represents Japan.