Former world number one Serena Williams must rethink her approach to Grand Slams after her latest bid to win a record-equalling 24th major prize came unstuck at Melbourne Park, her coach Patrick Mouratoglou has said.
The 38-year-old American, who is looking to match Australian great Margaret Court's record, has reached four Grand Slam finals since giving birth to daughter Olympia in 2017 but failed to win any of them.
She arrived at this year's Australian Open having won the Auckland Classic title but was beaten by China's Wang Qiang in the third round.
"We have to accept the fact that it's not working," Mouratoglou told the BBC.
"We have to face reality, but she's positive that she can make it, otherwise she probably wouldn't be on a tennis court anymore. She believes she can and I believe it too. She's not that far, but we have to change a few things.
"Maybe come back with a different angle, strategy and goals so she can make it. She does feel positive, she feels negative too because it's a failure when she doesn't win a Grand Slam."
Mouratoglou said time was not on Williams' side in the pursuit of the record.
"She had everything to retire, 23 Grand Slam titles ... it's difficult to know how many chances she'll have, I don't know how long she's going to be able to play, but being able to reach four Grand Slam finals says a lot about her level.
"Her level is good enough but we have to understand what's going on, why she's not able to win. There's a big difference between reaching a final and winning one."