Remember, Thomas and his Pistons teammates infamously walked off the court after getting their asses kicked by the '91 Chicago Bulls in the Eastern Conf. Finals without shaking hands.

Thomas, now 58, was not only villainized in the media for being a bad sport -- but Michael Jordan took the snub personally. They still don't get along.

The incident was featured in Sunday's new episode of "The Last Dance" ... and Monday morning, Thomas had more to add when he joined ESPN's "Get Up."

"Why I'm personally hurt is another reason why I'm here," Thomas said ... "Because being left off the Dream Team, that personally hurt me."

Thomas says he doesn't know why he was not selected -- but it's obvious he believes it's because he dissed Michael Jordan by not shaking his hand after that '91 series.

Thomas -- one of the best NBA players alive at the time -- says his resume should have made him a lock for the Dream Team, which is why he thinks the non-selection had nothing to do with his talent.

"If I'm not apart of the Dream Team because a lapse in emotion in terms of not shaking someone's hand ... if that's the reason why I didn't make the Dream Team, then I am more disappointed today than I was back then when I wasn't selected."

Thomas -- who had made the NBA All-Star team every year from '82 to '93 -- explained, "The only thing that's missing from my resume is not being on the Dream Team."

The man's got a point -- Thomas was one of the best players in the league at the time ... and had 2 NBA titles and was a 10-time All-Star at the time.

It's something Thomas has stressed for years ... he revealed in 2013 he felt disrespected by the Bulls, but would "absolutely" shake hands if he could do it all over again.