LOS ANGELES: Former tennis world number one Maria Sharapova will be holding a news conference in Los Angeles on Monday to make 'a major announcement', though no other details were given by her manager on Sunday. Sharapova's management company, IMG, declined to tell Reuters via email what topic had prompted the news conference but added: 'It will be very big news.' Monday's announcement will come just four days after Sharapova said she was withdrawing from this month's BNP Paribas Open at Indian Wells in California due to a persistent arm injury. The five-times grand slam champion has been troubled by her left forearm since the start of the year when she pulled out of an Australian Open warm-up tournament in Brisbane. Sharapova lost to Serena Williams in the quarter-finals of the Australian Open in January and has not competed since then. The 28-year-old Russian has suffered from assorted injuries over the past decade, and required shoulder surgery in 2008 that led to her being sidelined for nine months. Sharapova also missed the second half of the 2013 season because of a shoulder injury. Currently ranked seventh, Sharapova claimed her most recent grand slam crown at the 2014 French Open and has won 35 career titles on the WTA Tour. She has numerous business interests off the court, including a very successful apparel collection.