The two left pitlane running nose to tail and moments later went side-by-side and were not giving each other any space coming out of Turn 11.
Ferrucci, coming up the inside, managed to get by Grosjean’s #77 Juncos Hollinger Racing Chevrolet as they approached traffic heading into Turn 12.
A replay showed Ferrucci raising his hand above the aeroscreen of his #14 AJ Foyt Racing Chevrolet and provided a middle finger salute to the 38-year-old Swiss-born Frenchman.
Ferrucci finished ninth in the session, with Grosjean ending up 13th.
When the 30-minute session was over, Ferrucci mentioned there was payback that dates back to the last round at Barber.
“Man, he drove into me at Barber in the warm-up for no reason,” said Ferrucci. “I'm simply just returning the favour, my friend. It's not Formula 1 anymore; you can hit people with these cars and be fine.
“You want to turn it into me when I have the inside? I'm not lifting. I'm sorry. I had the corner and that's on him. If he doesn't like it, then come over here and talk to me about it.”
Ferrucci was quick to point out that there is nothing that precedes the incident at Barber, but he also won’t tolerate being pushed around.
“No, that's kind of where it started,” Ferrucci said. “I don't really have a beef with the guy. He's a nice dude, but you got to have a little bit more respect for your competitors on track.
“It's no sense me banging wheels with me at Barber. I'm on the inside this time. It's my corner and you want to turn into me, so be it. But like I said, I'm not lifting.”
For his part, Ferrucci believes the close racing will continue in today's Indy GP.
“I think we'll be able to pass,” Ferrucci said. “This track's notorious for having good racing, not just on the Speedway, but for the GP. We'll see.
“It's gonna be tight out there. It's real close. The field's real tight this year. Everyone's so good. There's very little discrepancy. You're more or less capitalizing on mistakes for other people.”
