Serena Williams' coach and rumored boyfriend mentioned that she "still has a margin for improvement that is enormous," reaffirming his rumored longtime commitment to her tennis career.

He also revealed during an interview with the New York Times that she is perhaps one of the best tennis players he has coached, leaving many wondering if he'll stay with her until retirement.

"Serena will never drop her guard. She will stop perhaps, but she won't drop her guard. She won't be 50th in the world, that's for sure. She wouldn't accept it from herself. It's not the style of the maison," he told the New York Times.

"It can't hurt, that's for sure. For sure it helps. She told me all the trophies we win when we work together we'll put them in the academy. They are in the entry. We reorganized. We made a big room like a players' lounge in the entry with the bar and put a trophy case there, which is already full."

But Serena Williams posted ominous messages that appear to talk about her personal life on Twitter, leaving many wondering if she has dumped her coach Patrick Mouratoglou as a boyfriend.

"No it's not forever. It means until they or you are finished," the American tennis star wrote in a post.

"When it comes to relationships - forever could have a different meanings for sure - long list," responded one Twitter fan on her page.

Serena Williams might have given her coach and rumored boyfriend Patrick Mouratoglou a scare, but quickly avoided it - a fan on Twitter asked her if she would twerk if she wins the Australian Open and she quickly responded saying "Lol no way"

Other fans responded to the post also responded "Lmfao.. good answer!"