Two-time Olympic champion Sir Andy Murray has pulled out of the men's singles competition in Tokyo due to a quad strain.

The 34-year-old - defending champion from Rio 2016 and London 2012 - was due to get his competition underway against Canadian hotshot Felix Auger-Aliassime today but has been forced to withdraw at the 11th hour.

The decision came after discussion with medical staff, who recommended he drop out of the intensive singles competition but cleared him to continue on with the doubles tournament alongside Joe Salisbury.

In a statement, the two-time Wimbledon victor said: "I am really disappointed at having to withdraw but the medical staff have advised me against playing in both events, so I have made the difficult decision to withdraw from the singles and focus on playing doubles with Joe."

The withdrawal of Murray is good news for Serbia's Novak Djokovic in his quest to become the first male tennis player in history to win the so-called 'Golden Slam' - all four Majors and the Olympics in the same calendar year.