The 27-year-old turned out for Andretti Autosport in Buenos Aires last month, his series debut, but is unable to compete in the March 14 race..
Andretti has IndyCar obligations to fulfill, with the 2015 season kicking off on March 29.
Had to bow out of the Miami @FIAformulaE race due to a schedule conflict . Bummer.
— Marco Andretti (@MarcoAndretti) February 10, 2015
It is not yet clear who will replace the American, although Matthew Brabham seems the most obvious option, with the 20-year-old having turned out for the team in rounds two and three.