The news comes as somewhat of a surprise but the Spaniard has been told he has the full backing and support of McLaren and engine partner Honda.
Alonso will hit the speedway circuit in Indiana on Sunday, May 28 – the same day the prestigious Monte Carlo F1 race takes place.
The veteran will be racing for the Honda-powered Andretti team.
After a shaky start to the 2017 season, McLaren have yet to announce who will replace Alonso behind the F1 wheel – but there is a possibility that Jenson Button could return.
Welcome to the crew @alo_oficial. Look forward to working with you next month... ๐๐ผ๐๐ผ #101 #indy500
— Alexander Rossi (@AlexanderRossi) April 12, 2017
Weโre going to #Indycar! @alo_oficial will race the 2017 #Indy500 with McLaren-Honda-Andretti. Full details at https://t.co/Z3pNyQDkZ7 #F1 pic.twitter.com/uN07VRrSIR
— Honda Racing F1 (@HondaRacingF1) April 12, 2017
.@alo_oficial what an absolute legend. Could he win Indy 500 at first attempt? Graham Hill did it. ALO wants to win Monaco, Indy & Le Mans
— Andrew Benson (@andrewbensonf1) April 12, 2017