TENNIS: Serena Williams has her coach on a mission to recapture her "unplayable" game.
The world No.2 will take on Australian-born Brit Johanna Konta today and the 22-time grand slam champion's coach Patrick Mouratoglou has admitted he is concerned with the match-up.
He said Williams' court movement hasn't been up to scratch and could be firmly tested in her maiden meeting with the ninth seed.
She "found a way to win" against Barbora Strycova on Monday, he said, despite being broken four times and landing just 45% of first serves.
And some tweaking is required.
"There is no explanation why she doesn't move as well as she can," Mouratoglou said.
"We have to solve that, especially against Konta, who is someone who plays so fast, so aggressive, takes the ball early. You can't afford to be slow.
"It will be difficult. Konta is someone I look at. Last year she was already impressive. I saw her play at the start of the year and she has been the player that has impressed me most.
"It was not that she won the Sydney (International, the week before the Open) but it was also the way that she won it. She has no doubts at the moment.
"She moves super-fast. From every position, she tries to hit every shot. She is so aggressive every time she hits the ball."
Konta is on a nine-match winning streak and has dropped just 22 games so far at the Australian Open.
Mouratoglou - who has coached Williams since 2012 - was planning a range of "exercises" to sharpen his charge against the Brit's attacking game style.
And he wants to see Serena's aggression in full flight.
"When she does that I think she's almost unplayable," he told ESPN.
"She takes the ball early, she goes to the open space and then she comes to the net to finish up with a swing volley overhead, or a volley - she does that so well, and of course we work a lot on it.
"I know she's 35 but I think she has a future, she can still have her game move forward and get better."
Williams said this week that she has watched Konta's game closely, and while the Briton said that was "nice to hear", she knows the great will be coming for her.
"I don't necessarily think that Serena Williams possibly gets too worried," Konta said.
"Just the amount of experience she has, I'm sure she's got her system and her method for preparing for every match, regardless who she plays, and I'm sure she's going to be applying that method against me."
Karolina Pliskova (CZE)  v Mirjana Lucic-Baroni (CRO)
Johanna Konta (GBR)  v Serena Williams (USA) 
David Goffin (BEL)  v Grigor Dimitrov (BUL) 
Rafael Nadal (ESP)  v Milos Raonic (CAN)