D-Mac stirred up the football world just a few months ago when he told the guys on the "TMZ Sports" TV show (airing weeknights on FS1) that he belongs in Canton.
Moon saw the interview ... and wishes McNabb had been a little more neutral on his stance -- saying there's ZERO need for D-Mac to plead his case.
"I think he deserves to be in the Hall of Fame," Moon told the guys. "If you look at his numbers and what he did over the course of his career -- he went to four NFC championship games, he went to a Super Bowl."
But, Warren added, "I just think when you start campaigning for this, it's not a good look."
McNabb was just named one of 122 finalists for the 2020 Hall of Fame ... and he immediately took to Twitter saying, "Let's make sure we go out and vote. 'Fly Eagles Fly.'"
Moon thinks that's just unnecessary, saying, "I wish he would have never made any comments about it."
By the way, we also asked Moon how he'd fare in today's NFL ... and you gotta hear why the former Oiler thinks he'd put up some OBSCENE numbers as a passer in 2019!!!