Rahal had issues with his engine Friday morning and switched it out before its mile limit.
Kanaan and Viso put in new engines earlier this week after last weekend's race in Milwaukee.
IndyCar also has updated the rules for the qualifying heat races set for later Friday. The grids for those three heats will be set by practice times, and IndyCar says any car that interferes with another will have its best two timed laps disallowed. If a car breaks the rules again, its session times will be voided and it'll be banned from the rest of practice.