Olympic silver medallist Juan Martin del Potro will miss the Australian Open next month and the Auckland Classic in New Zealand due to fitness concerns.
The 28-year-old has struggled with wrist problems since reaching a career-high fourth in the world in 2010.
After missing most of the 2014 and 2015 seasons, del Potro returned in 2016 to reach the Olympic final and help Argentina win a first Davis Cup.
He told Auckland Classic organisers he has "not had sufficient recovery time".
Del Potro began 2016 ranked 1,042th but finished at 38th after a year that included wins over Stan Wawrinka, Novak Djokovic, Rafael Nadal and Andy Murray.