Rossi went on to finish second, by far his best ever result on the Indianapolis Motor Speedway road course, but felt that he could have threatened eventual winner Josef Newgarden of Team Penske for victory without that penalty.
Officials ordered him to fall behind the Chip Ganassi Racing ace after a tough duel saw him run wide at Turn 6, the right-hander coming onto the back straight.
This comes just two months after Rossi was assessed a drive-through penalty for mild pitlane contact with another car in the Indianapolis 500.
Immediately after stepping from the cockpit of his Andretti Autosport-Honda, Rossi commented: “I did two wheels over the white line, we talked about the reference point, and we still get penalized. Two times at Indianapolis we have penalties, I don’t know what to say.
“Hats off to the team, we’ve never been good here so to get on the podium is fantastic and testament to Honda. It’s been a huge effort to find some sort of pace here. It’s weird that these penalties keep happening, there’s not a lot of explanation from our side.”
In the press conference afterward, Rossi explained: “The penalty cost us a lot of time and track position. We were stuck behind lapped cars there. That’s where Josef [Newgarden] was able to pull a big gap on us. He was on blacks [Firestone’s harder primary tire compound], we were on reds [softer]. I’m not saying we would have won but we at least could have given him a fight.
“So we need to discuss that, get to the bottom of it. It’s a shame that happened. I’m happy we were able to recover to second, but definitely if we look back at the race, there’s a lot that was taken away from us and left on the table…
“I didn’t go beyond the time line and I put two wheels over the white line – you’re not allowed to go four [wheels over].”
Asked to elaborate further on what annoyed him about his penalty, ex-Formula 1 driver Rossi made comparisons with other motorsport categories.
“It’s something we need to look at,” he said. “Other series assess time penalties at the end of a race, which gives you time to assess it, argue it. Giving penalties mid-race for very minor things… If there’s contact where you’re taking someone out of a race, if you’re hitting people in pitlane – personnel – and for major issues, I understand it. But for little ticky-tack type things, would time penalties be more appropriate? I don’t know; we’ll have to talk about it.
“At the end of the day, maybe that’s not written in the rulebooks, so maybe the officials’ hands are tied in terms of how they can dish out penalties – I don’t know.
“But we need to talk about it, learn from it and understand why that happened, and make sure it doesn’t happen again.”