Former US Open champion Emma Raducanu has withdrawn from this week’s WTA event in Auckland because of a back problem.

The 22-year-old was due to play Robin Montgomery of the United States in the first round of the ASB Classic on Tuesday.

She will now fly to Melbourne to continue her preparations for the Australian Open, which gets underway on January 12.

“Tried my best to be ready,” she said. “I love Auckland and the fans here, but unfortunately I picked up a back niggle and won’t be ready in time.

Raducanu sprained ligaments in her foot in Seoul in September and could only play three further matches last season.

She won them all, on national duty for Great Britain at the Billie Jean King Cup Finals, but will now head into the first Grand Slam of the season with no match practice.

The former British no.1 will not be seeded for the Australian Open as a result of her currently being 56th on the WTA Rankings.