Rivera -- who coached Newton with the Carolina Panthers from 2011 to 2019 -- made the comment Monday on 670 The Score. Newton agreed to a one-year contract with the Patriots on Sunday after a long period of going unsigned in free agency.
"He's headed in the right direction," Rivera said of Newton. "I mean, he's probably about as healthy as it gets from what I've seen on video. I think he's ready to bust out."
Newton, 31, completed a career-high 67.9 percent of his throws for 3,395 yards, 24 touchdowns and 13 interceptions in 14 starts for the Panthers in 2018. The 2015 NFL MVP also had 488 rushing yards and four rushing touchdowns during that campaign, which was his last full season. Newton appeared in just two games in 2019 due to a foot injury. He also dealt with shoulder issues at the end of his tenure with the Panthers.
"I would never bet against the young man, that's for sure," Rivera said.
Rivera also said he believes the coronavirus pandemic, which prevented teams from in-person workouts, was one of the reasons more teams didn't try to sign Newton. The former Panthers star was also linked to the Los Angeles Chargers, Cleveland Browns and Rivera's Redskins.
Newton has posted videos of himself at workouts throughout the off-season on social media. He also has posted footage of himself throwing deep passes, an indicator that his shoulder is likely healthy. The three-time Pro Bowl selection posted a YouTube video on Monday titled "Farewell Carolina, hello New England."
Newton said he was "angry" and felt "let down" by the way his tenure with the Panthers ended. He also said he "never wanted to leave Carolina" and he only asked for a trade after the team decided the parties should part ways. The Panthers released Newton on March 24.