Rick Stroud of the Tampa Bay Times first reported the move. The team later announced they released Martin.
Martin's six years in Tampa were characterized by extreme highs and severe lows. The 5-foot-9 back burst onto the scene as a rookie, running for 1,454 yards on 319 carries with 11 rushing TDs. Martin then went into a two-year swoon, falling under the 500-yard mark and missing 15 games. The pint-sized back returned to form in 2015, galloping for 1,402 yards, second-most in the NFL, en route to an All-Pro bid.
The second 1,400-plus yard season of his career earned Martin a new five-year, $35.75 million contract in Tampa. Martin lasted just two years of that deal. His four-game suspension for violating the league's performance-enhancing drugs policy late in 2016 negated the rest of his guaranteed money, allowing the Bucs to cut him without any salary-cap ramifications.
The past two seasons Martin has been one of the least efficient running backs in the NFL. He struggled to break tackles, lost his early-career burst and struggled to gain positive yards on most carries. In 2016 and 2017 he averaged 2.9 yards per carry on 282 combined carries.
That stellar running back draft class, coupled with several solid mid-level free agents (Dion Lewis, Carlos Hyde, Jerick McKinnon), will make it difficult for the 29-year-old Martin to land a cushy job. Martin's best bet to continue his pro career is likely as a rotational player on a one-year, incentive-laden "prove-it" contract in 2018.