Either Andre Agassi is really secure about his marriage to Steffi Graf or Graf is really secure about her tennis career to hear her husband support Serena Williams' bid to pass her in Grand Slams.

Or both.

Agassi told Reuters that he is watching intently as the 33-year-old Williams sets her sights on her next major accomplishment - surpassing Graf's professional era record of 22 Grand Slam wins - to solidify her legacy in tennis.

"She's arguably the greatest ever, it would be easy to argue that regardless of 22 or not," the former men's No. 1 player in the world said of the current No. 1 women's player in the world. "Records are meant to be broken and if Serena does it would be a beautiful thing to watch."

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Agassi pointed out that his own record of four Australian Open Grand Slams was shoved aside last month as Novak Djokovic won his fifth.

"I just found out my four Australian Opens was broken by (Novak) Djokovic," he laughed. "But I was just thrilled to watch a good match. It's great for the game."

Maria Sharapova resigned to the fact she may never beat Serena Williams?

It's a viewpoint Agassi says his wife shares.

"She was thrilled with her career, she had no regrets, she did everything she could do and that's all she ever cared about," Agassi told Reuters TV at the launch of the BILT by Agassi & Reyes range of gym machines near London.

"But what Serena is doing is remarkable."

Margaret Court hold the all-time record for Grand Slams with 24, and Graf owns the professional era record with 22.

After beating Maria Sharapova in the Australian Open final, Williams shows no signs of slowing down. But at least Agassi and Graf still have some time to prepare themselves for a potential Serena takeover. Even if Serena wins every major that comes her way, she would surpass Graf until the 2016 Australian Open.