Juan Martin del Potro does not expect to compete in next month's Australian Open as he continues to battle with his fitness after two years away from tennis.
The Argentine made a stunning comeback to the ATP Tour in 2016 after struggling with a wrist injury, reaching the final of the Olympic Games tournament and the US Open last eight.
He was also instrumental in guiding Argentina to Davis Cup glory, winning both his singles matches in the final against Croatia before Federico Delbonis secured the title.
Much is expected of the former world number four in 2017, but Del Potro says it will take time to get back to his best.
"What I need is to have someone get me physically fit enough to last the whole year," the 2009 US Open champion is quoted as saying by Argentine newspaper Ole.
"There's a fortnight to the Australia Open and I'm unlikely to make that objective.
"We're looking at what the priority is. If tennis waited for me for two years, Australia can wait for me for one more."
And the 28-year-old also revealed he may miss the opening game of Argentina's Davis Cup defence against Italy in February due to the surface in Buenos Aires.
He added: "There's still some time to the first tie against Italy, but not so much and it's going to be on clay and that's a surface I struggle on."