Tokyo, July 25 : Defending champion Andy Murray of Great Britain withdrew from the singles draw at the Tokyo Olympics on Sunday citing a right quad injury. The 34-year-old plans to continue in the doubles draw with Joe Salisbury. The former world No. 1 was scheduled to play Felix Auger-Aliassime of Canada in the opening round. "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," Murray said according to olympics.com. The former world No. 1 is a two-time Olympic singles gold medallist (2012 London and 2016 Rio). Murray teamed with Salisbury on Saturday to upset second seeds Pierre-Hugues Herbert and Nicolas Mahut of France in the first round of the doubles draw. The Britons will play Germans Kevin Krawietz and Tim Puetz in the second round. Murray, who was scheduled to play Canadian Felix Auger-Aliassime in singles, was replaced by Australian Max Purcell. Hungarian Marton Fucsovics also withdrew due to a right shoulder strain, and was replaced by Australian Luke Saville. /IANS