Reigning Olympic champion Andy Murray has called it quits on the 2018 season.
The former World No.1 pulled out of the China Open in Beijing in October with an ankle problem after he lost 6-4, 6-4, to Spaniard Fernando Verdasco in Shenzhen.
Murray, who won Olympic gold at London 2012 and made history by retaining his crown at Rio 2016, dropped to No.311 in the rankings after he spent almost a year out recovering from hip surgery.
The 31-year-old ends his 2018 campaign with seven wins and five losses.
Out since Wimbledon 2017, Murray made a much-anticipated return to the Tour at The Queen's Club in June where he fell in three sets to Nick Kyrgios.
There were encouraging signs: a straight-sets win over former World No. 3 Stan Wawrinka at the Nature Valley International, three wins that took him to the quarter-final of the Citi Open and a straight-sets victory over top seed and defending champion David Goffin at the Shenzhen Open.
But the loss to Verdasco in the quarter-finals at Shenzhen on Friday was a repeat of their US Open second round match in August, making it two wins in a month for the 34-year-old.
Verdasco had previously suffered eight consecutive defeats to the Scot stretching back nine years.
The loss and the ankle problem prompted Murray to call it in for 2018.
The double Olympic champ will now set his sights on 2019 and potentially build back up to an unprecedented three-in-row gold at Tokyo 2020.