In the closing stages of second practice at Mugello on Friday afternoon, Gresini’s Marquez was forced to abort a flying lap when he came across a slow Bagnaia on the approach to Turn 12.
Marquez was enraged by this and vented his frustrations to Bagnaia on his bike as the pair rounded the corner.
Both riders secured a place directly into Saturday’s Q2 qualifying, with Bagnaia leading second practice.
However, he will be forced to drop three places on the grid for Sunday’s Italian GP at Mugello. The penalty will not apply for the sprint.
Prior to the penalty, Bagnaia says he saw no blue flags warning him of Marquez approaching behind and feels the Gresini rider’s actions were typical.
“Yeah, like always,” he said of Marquez’s outburst.
“I was, first of all, without blue flags. And then I was out of the line, I braked more in front to be out and like always he’s a good showman.
“So, he did this kind of gesturing on his bike. Like always.”
For his part, Marquez says he was being held up by Bagnaia from the second sector of that lap.
“Well, I was coming on a hot lap, improving my lap times,” Marquez said. “I saw Pecco in front from sector two being really slow in the middle of the track.
“I was expecting him to watch behind to see me, but he never did it. Going into Turn 12 he was completely in the middle of the line, on the racing line.
“I was able to avoid him, but I had to cut the throttle. So, for me, it’s quite clear what happened.”
When it was put to him that Bagnaia felt he overreacted, Marquez added: “He also said he was out of the line. And it’s not true.
“So, I will not say any more. He knows what happened, I know what happened. So, that’s it.”
If Bagnaia is found guilty of irresponsible riding by the FIM stewards, he could be facing a grid penalty for Sunday’s grand prix.