2017 Wimbledon, Rafael Nadal
Tennis - Wimbledon - London, Britain - July 10, 2017 Spain’s Rafael Nadal reacts after losing his fourth round match against Luxembourg’s Gilles Muller Reuters / Matthew Childs

World No. 1 Rafael Nadal has vowed to appear at the 2018 Australian Open after pulling out of the Brisbane International. Nadal had previously committed to play the ATP 250 series at the Queensland Tennis Centre, in the lead-up to the first Grand Slam of the new season at Melbourne Park.

A year ago, Nadal returned from his wrist injury at the Brisbane International and advanced to the quarter-finals where he lost to Canadian Milos Raonic. The Spaniard benefitted by playing in Brisbane as he played spectacular tennis leading into the Australian Open final before falling to arch-rival Roger Federer. This year, however, Nadal is not devoid of match practice, after playing 17 tournaments in 2017.

"I am sorry to announce I won’t be coming to Brisbane this year. My intention was to play but I am still not ready after last year’s long season and the late start of my preparation. I had a great time there and it was a great start to the month I spent in Australia," Nadal said via Twitter on Thursday.

Rafael Nadal pulls out of 2018 Brisbane International

Until Wednesday, organisers of the Brisbane International were holding out hope for Nadal, who recently pulled out of the Mubadala World Tennis Championship -- a year-ending exhibition event in Abu Dhabi. Nadal has reportedly yet to heal from the knee injury that forced him to forfeit his Nitto ATP Finals match against David Goffin in November.

There is still some uncertainty over the participation of former World No. 1 Andy Murray, who hasn’t stepped on the court since his fourth-round defeat to American Sam Querrey in this year's Wimbledon. Earlier this month, the English media reported that Murray was expected to fly out to Australia after the Christmas break.

Despite a remarkable 2017, injuries have halted Rafael Nadal's momentum entering the new calendar year. After pulling out the Paris Masters, ATP Finals, Abu Dhabi exhibition and Brisbane International due to injuries, Nadal is no longer viewed as a favourite to prevail at the 2018 Australian Open which starts Jan. 15.