Brisbane - Japanese star Kei Nishikori has withdrawn from the season-opening Brisbane International as he recovers from a wrist injury.

Nishikori, 27, has been out of action for more than four months, dropping to 22 in the world rankings.

"I am so disappointed to miss Brisbane this year. For years, it's been my first tournament of the season and I always feel so at home there," Nishikori said on the tournament's official Twitter account.

Nishikori said last month he had chosen rehabilitation over surgery to repair the damage and was targeting a return to action at the Brisbane International to prepare for the Australian Open.

Meanwhile, US Open champion Sloane Stephens has also been ruled out of the Brisbane women's tournament with a knee injury.

"Sloane Stephens needs an extra week's rehab on her knee, meaning she will now not play the Brisbane International," the organisers tweeted.

The Brisbane International takes place from December 31 to January 7.