Nadal, who pulled out of the Mexican Open in Acapulco earlier this week, continues to be hindered by a hip injury that has plagued him for several months.
Nadal initially hurt his hip in January's Australian Open, when he retired after being down 2-0 in the fifth set of the quarterfinals against Marin Cilic. I won't be able to play in Indian Wells or Miami and the target is now to recover to be on the ground for the [clay-court] season.
'It was very painful to retire from Acapulco and it's very hard as well to not play in the USA.
Nadal was scheduled to vie for his fourth BNP Paribas Open title beginning next week, but on Friday, he and tournament organizers announced that he will not be able to participate. "I'll miss you, but I'll do my best to be back in 2019".
His exit also means Federer could build on his ranking lead, though has to defend both Indian Wells and Miami titles while Nadal loses points from the Miami final points and the Indian Wells fourth round.More news: Trump attacks Sessions as 'disgraceful' - and the attorney general pushes back
Rafael Nadal has been forced to withdraw from the Masters Series events in Indian Wells and Miami.
That was the only event played by Nadal this year so far.
The Monte-Carlo Masters gets under way on April 15, with Barcelona (April 23), Madrid (May 6) and Rome (May 13) to follow before the French Open on May 27.
The 16-time grand slam victor initially suggested returning at Indian Wells, which begins on 8 March, would be a "great goal" for him but having since sought further medical advice, the Spaniard has now opted to skip the Sunshine Double and focus exclusively on his recovery.