World number three Naomi Osaka and two-time major winner Victoria Azarenka on Saturday, pulled out of Australian Open warm-up tournaments due to injury concerns, reported AFP. They now join a list players that include Serena Williams and Simona Halep, who have withdrawn because of injury issues.

US Open champion Osaka would have taken on Elise Mertens in the Gippsland Trophy semi-final but withdrew. The 2019 Australian Open winner said, “Sorry to Tennis Australia and the fans to have to withdraw today. 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 powered past Irina-Camelia Begu 7-5, 6-1 in 76 minutes on Friday night and looked in sublime form. She has now joined Williams, who pulled out of her semi-final clash against world number one Ashleigh Barty with a shoulder injury on Friday.

The 39-year-old  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.