Andy Murray has withdrawn from the Brisbane International due to the hip problem, leaving his participation at the Australian Open in doubt.
Murray has not played competitively since the quarter-finals of Wimbledon last year, when he was beaten in five sets by Sam Querrey, because of the hip issues that hampered his 2017 campaign.
He made his comeback at the Mubadala World Tennis Championship on Friday, looking rusty in a one-set exhibition with Roberto Bautista Agut.
And his hopes of competing in a Melbourne at a slam where he has reached the final five times but never won have now been dealt a blow.
Murray had been due to face Ryan Harrison in the second round in Brisbane, but instead his withdrawal leaves his readiness to play at the opening major of the year looking questionable.
The three-time grand slam singles champion follows Rafael Nadal in pulling out of the tournament, the Spaniard set to head to the Australian Open without having played a warm-up event.
Novak Djokovic's participation in Melbourne is also in doubt after his withdrawal from the Qatar Open because of an elbow problem that has kept him off the circuit since Wimbledon.
The respective fitness concerns of the trio appear to clear the path for Roger Federer to improve his record of 19 grand slam titles.
Federer prevailed at the Australian Open and Wimbledon last year and is the clear favourite to defend the first of those crowns and, at the age of 36, win a 20th major title.
