Nill Kyrgios knows more than most that her son doesn't do things by halves. And last Tuesday's practice session ahead of next week's Australian Open was no exception. 
"He was going all out," Mrs Kyrgios said. "And then he lunged for a ball and said, 'Oh, I think I've pulled something'."
That twinge was at the back of his right ankle - likely a muscle pinch rather than an Achilles injury. It led to him retiring hurt from the Kooyong Classic on Wednesday, after making it to the second set against Belgian David Goffin.
With the 20-year-old's first Australian Open as a seeded player due to begin on Monday, Mrs Kyrgios said it was a precautionary decision.
She said Kyrgios' physiotherapist Will Maher and strength and conditioning coach Matthew James had arrived in Melbourne just in time, and would be on the case.
"With rest, ice and Will (Maher) treating him two to three times a day to loosen up the muscles and stop inflammation, I'm sure he will be fine," she said.
The Kyrgios family will be reuniting in Melbourne for the Open -??? with parents Nill and George joined by siblings Hali, who jets in from Japan on Tuesday, and Cristos. They will stick to tradition and stay at the same East Melbourne hotel they have been booking into since Kyrgios was playing in the juniors.
"It feels like home," Mrs Kyrgios said. "And you can easily walk back and forth."
Kyrgios, who will be seeded 29 at the Open, was scheduled to have a hit up at Hisense Arena against the tournament's second seed Andy Murray on Thursday afternoon.
However Canberra-based Kyrgios was a no-show, leaving Murray to train with coach Amelie Mauresmo.
History is fast building between world number two Andy Murray and the Australian up-and-comer.
It was Murray who knocked the then 19-year-old out of last year's Australian Open, denying him a place in the semifinals at his home grand slam.
And only last week, Kyrgios dismissed the Scot at the Hopman Cup in Perth, as Australia steamed towards its first win in 17 years.
At number 30 in the world, Kyrgios is Australia's second-highest ranked player heading into the Australian Open. Bernard Tomic, who climbed one spot to number 17 in the latest ATP rankings, is the country's top-ranked male while Lleyton Hewitt enters his farewell Australian Open at number 306.
Hewitt, 34, trained at Rod Laver Arena on Thursday, as did defending champion Novak Djokovic.
Sporting a grey T-shirt depicting Mickey Mouse playing tennis, Djokovic had 2014 Australian Open winner Stan Wawrinka as his hitting partner.