Del Potro, ranked fifth in the world, was unable to defend his BNP Paribas Open title in Indian Wells this week as he underwent treatment on the injured right knee.
It has not recovered sufficiently to allow him to play in Miami, which begins next week.
"Unfortunately I won’t be able to play in Miami this year," Del Potro said on Twitter. "Looking forward to coming back in 2020!"
A source, speaking on condition of anonymity, told Reuters the 30-year-old might have to have surgery on the fractured kneecap that has kept his appearances to a bare minimum since October when he withdrew from the Shanghai Masters.
The injury came at the tail-end of Del Potro’s best season in years. He won titles in Indian Wells and Acapulco and reached the final of the U.S. Open to climb to a career high No. 3 in the world.
(Reporting by Ramiro Scandolo, writing by Andrew Downie; Editing by Peter Rutherford)
