"If he's not (the Patriots' next coach), then that would've been the absolute dumbest move in the history of sports," Weis said on SiriusXM.
Multiple outlets have reported that the Patriots haven't promised McDaniels their head coaching position when Bill Belichick opts to leave.
Weis, who served as the Patriots' offensive coordinator from 2000-04, said that he expects McDaniels to replace Belichick at some point.
"In 31 cities, I'd say the odds of them hiring him (as head coach) would be slim to none," the 61-year-old Weis said. "But in one city, he's endeared himself. Let me be the first to lay a wager in Las Vegas that when Belichick leaves, Josh McDaniels is the next head coach in New England. It's like Secretariat running right now. I'd say the odds of that happening are almost a hundred percent."
Weis left New England for Notre Dame, with which he recorded a 35-27 mark before being fired in 2009. He went on to be the head coach of Kansas, posting a 6-22 record in two-plus seasons before being fired in 2014.