Summary Naomi Osaka and Azarenka joined Serena Williams and Simona Halep with injury concerns.
MELBOURNE (AFP) - World number three Naomi Osaka and two-time major winner Victoria Azarenka pulled out of Australian Open warm-up tournaments Saturday, joining Serena Williams and Simona Halep with injury concerns.
Japan s Osaka, the US Open champion and 2019 Australian Open winner, was set to play Elise Mertens in the Gippsland Trophy semi-final but withdrew.
"Sorry to Tennis Australia and the fans to have to withdraw today," she said on the WTA s Twitter account.
"I have a niggling injury and in light of the AO on the horizon I need to be cautious. I look forward to competing next week."
Osaka had looked in fine form powering past Irina-Camelia Begu 7-5, 6-1 in 76 minutes on Friday night.
She joined Williams as a late withdrawal after the American pulled out of her semi-final clash against world number one Ashleigh Barty with a shoulder injury Friday.
Williams, 39, had ousted fellow American Danielle Collins 6-2, 4-6, 10-6 in the Yarra Valley Classic but withdrew hours later despite showing no ill effects during the match.
Two-time Australian Open champion Azarenka was also a casualty Saturday, opting not to play her quarter-final clash with Anett Kontaveit at the Grampians Trophy due to a lower-back injury.
Mertens will play Ekaterina Alexandrova or Kaia Kanepi in the Gippsland Trophy final while Barty faces two-time Grand Slam champion Garbine Muguruza or Marketa Vondrousova in the Yarra Valley Classic decider.
While Williams and Osaka s withdrawals appear precautionary, there might be more concern over Halep s fitness.
The world number two was thrashed by Alexandrova 6-2, 6-1 in the Gippsland Trophy quarter-finals, where she appeared hampered by a lower-back injury.
Halep strapped on a back brace after calling for medical attention after the first set, in a lopsided contest lasting just one hour.
