The 30-year-old Japanese, who has not played since losing to Alex de Minaur in the third round of the US Open and underwent minor elbow surgery in October, will also miss the inaugural ATP Cup team event in Australia.
* England's record goalscorer Wayne Rooney will make his debut for second-tier Derby against Barnsley on Thursday, the club's manager Phillip Cocu confirmed.
* Former world number one Maria Sharapova will open her 2020 campaign in Brisbane after being awarded a wild card by organisers, the five-time major winner announced on Monday (Dec 30). The 32-year-old Russian hasn't played since a first round loss to career-long rival Serena Williams at the US Open in August.
* Swedish star Zlatan Ibrahimovic will be officially presented as an AC Milan player on Jan 3, the Italian club confirmed on Monday (Dec 30). Ibrahimovic returns to the side on a six-month deal, promising to help rescue the struggling Serie A outfit's season.
* AC Milan have reached an agreement with Barcelona to sign French central defender Jean-Clair Todibo, according to reports in Italy on Monday (Dec 30). The 20-year-old would join the Italian league strugglers on loan with a €20-million (US$22.4 million) option to buy, Gazzetta Dello Sport reported.
* The Video Assistant Referee (VAR) should only overturn on-field decisions when there has been a "clear and obvious" error, according to one of football's leading international rules officials.
* David Beckham's Major League Soccer (MLS) team Inter Miami have named Diego Alonso as head coach ahead of their debut next season as the latest franchise in the fast-growing league.
* David Moyes returned as West Ham United manager on Monday (Dec 30), saying he was a winner determined to revive the club's Premier League fortunes and secure his own long-term future in East London. The 56-year-old saved the club from relegation in a six month stint at the helm in 2017-18 and returns with the task of lifting a side languishing in 17th in the standings and a point above the drop zone.
* Manchester United midfielder Paul Pogba is set to return for their Premier League visit to Arsenal on New Year's Day after sitting out Saturday's 2-0 win over Burnley as a precaution, manager Ole Gunnar Solskjaer has said.
* Monterrey won their first Mexican league title since 2010 on Sunday but they needed penalty kicks to do it after America beat the visitors 2-1 after extra time to tie the two-legged final at the Aztec stadium.
* AS Roma said on Monday (Dec 30) its holding company was in talks with a group led by US billionaire Daniel Friedkin about a sale of the Serie A football club though no formal deal had yet been agreed.