The gentlemen started their engines, but Keith Urban wasn’t one of them attending Sunday’s (May 29) Indianapolis 500.

A back injury forced him to cancel on his plans to ride with legendary driver Mario Andretti. Urban was going to perform — just ride in the two-seater with Andretti in front of the pace car at the start of the race.

Lady Gaga took Urban’s place to help kick off the 100th running of the Indy 500.