The former Colts first-round draft pick averaged just 3.14 yards per carry in two seasons as an afterthought third-stringer for San Diego.
Although the Chargers released Brown earlier this month, team president John Spanos believes the 28-year-old will turn his career around in New England.
"He is such a perfect Patriots signing," Spanos said Saturday night at the NFL owners meetings, via CSN New England's Tom Curran. "I would bet anything he's going to be a productive player for them."
"This past year, we drafted Melvin (Gordon) with the 15th pick and we had Woodhead and the opportunities just weren't there," Spanos explained. "And before that we had Ryan Mathews. He's a good player. It just didn't work out here but I believe it will for him there. Perfect player for them.
"And he's a guy who'll be the first guy in, does his work, does whatever he's asked and just keeps to himself. He's one of the players you really root for after they leave."
Brown's one-year, $965,000 contract suggests he will have a good chance to make the final roster on his own merits, though, as the new deal comes with $300,000 in guarantees.
With a high-cut build more closely resembling a wide receiver, Brown is never going to be a bowling ball between the tackles. His game tape from 23 touches in the 2015 regular-season finale, however, showed an elusiveness in making multiple Broncos defenders miss tackles en route to 91 yards.
As Spanos noted, a fresh-legged Brown makes for an intriguing bounceback candidate as a committee back in New England's wide open offense after two years of rest in San Diego.