Rafael Nadal described the idea of risking his health just to maintain the world No 1 ranking as “madness”.
Federer can narrow the gap on Nadal at the top of the ATP rankings if neither man play in their upcoming tournaments in Dubai and Mexico respectively.
Federer won the Australian Open last month to defend a vital 2000 ranking points, while an injured Nadal exited at the quart-final stage.
Nadal is hoping to be fit for Acapulco on February 26, having suffered a thigh injury in Melbourne.
But he insists he will not compete unless he is 100 per cent ready.
“I’m not going to commit any madness in order to keep the No 1 spot,” he said.
“The first thing is to be healthy, happy and eager to work.”
Rafael Nadal added: “At the moment I only think about recovering because for me the most important thing is to get well into the period between Monte Carlo and Roland Garros.
“I insist that I want to be happy and from there it is all more or less secondary.
“Logically, the season on the clay is set and my main goal is to return to be the best player in the world on the clay.”
As for Federer, he is down to play in Dubai but has refused to commit himself to the tournament just yet.
The 36-year-old was taken to five sets against Marin Cilic in the Australian Open final.
And he has since taken time off to recover from the tournament.