2 announced the news via Facebook on Friday, stating, "I'm sorry to write this, but my worst possible scenario has been confirmed".
Former world No. 3 Stan Wawrinka has withdrawn from the Miami Open and Indian Wells tournaments this month to continue his recovery from a persistent knee injury, the Swiss right-hander said on Thursday.
The 31-year-old Spaniard withdrew from this week's Acapulco Open in Mexico after a recurrence of the problem.
"They are both fantastic events, but coming back from a big surgery after having played a few tournaments, I have discussed with my team that it is best for me to build on the progress and go back to practice", Wawrinka said in a statement. "It hurt to retire in Acapulco, where I get so much support, but it's also painful not to be with my fans in the US for the American swing in March, something that has always been important to me".
It means Nadal would have been "defending" 690 points while Federer, who won both tournaments, could lose as many as 2000.
The 16-time Grand Slam champion would have been well placed to return to the top of the rankings in either Indian Wells or Miami had he secured victory in Acapulco.
He lost in the Australian Open second round in January, then the first round at the Rotterdam indoor tournament, before retiring from his second-round match last week in Marseille, France.
That was the only event played by Nadal this year so far.
The Indian Wells tournament begins March 7, while Miami commences two weeks later.