British number one Johanna Konta withdrew from the Sydney International for a second time in two days.
The 27-year-old was due to play Kiki Bertens as a lucky loser in the first round on Monday, having retired from her second-round qualifying match with a neck injury on Sunday.
No reason has been given yet for the latest withdrawal, which comes a week before the Australian Open.
Meanwhile, Heather Watson lost in the Hobart International first round.
British number two Watson was beaten 6-1 6-4 by Romania's Irina-Camelia Begu.
The tournaments in Sydney and Hobart are the final WTA events before the Australian Open, the first Grand Slam of the year, begins on 14 January.
Konta, ranked 37th in the world, reached the Australian Open semi-finals in 2016 and was a quarter-finalist in 2017, although she exited last year's tournament in the second round.
She changed coaches in October - appointing Dimitri Zavialoff to replace Michael Joyce - and has spoken of feeling positive about her chances in 2019 after a "very strong pre-season".