FLORHAM PARK, N.J. — When Stevan Ridley excelled as a running back at Louisiana State, he dreamed of earning a lucrative N.F.L. contract one day and the material pleasures it would bring. When he signed a relatively modest deal as a third-round draft choice of the New England Patriots in 2011, he drew motivation from knowing that free agency could yield the big money he desired once he proved himself.
Ridley showed he belonged by rushing for a career-high 1,263 yards and 12 touchdowns in his second season, and he tacked on 773 yards in 2013. He appeared to be on course for more solid results when he was New England’s leading rusher with 340 yards early last year in his final season before free agency.