New York Jets running back Curtis Martin has finally decided that enough is enough.
The NFL's fourth all-time leading rusher who hasn't played since the 2005 season, Martin announced his retirement Thursday.
Martin, 34, who has a bone-on-bone condition in his surgically repaired right knee, was on the physically-unable-to-perform list since the start of last season's training camp.
"Retirement is not an end but a beginning," Martin said. "It is not giving up a position but more of a passing of the baton. And it's definitely not a crossroad but a bridge that will further my pursuits within the NFL."
Martin underwent surgery in December 2005. At the time, it was believed to be an arthroscopic procedure, but more damage than expected was found in the knee.
Martin played 11 seasons in the NFL - three with the New England Patriots and eight with the Jets - and rushed for 14,101 yards and 90 touchdowns. His 3,518 rushing attempts is the third highest in league history. Martin also had 484 receptions for 3,329 yards.
A five-time Pro Bowler, Martin was signed as a restricted free agent by the Jets in March 1998. He is the franchise's all-time leading rusher with 10,302 yards.
In 2004, Martin won the rushing title with 1,697 yards and joined Barry Sanders as the only players to begin their careers with 10 consecutive 1,000-yard seasons.
The team acquired former Chicago Bears star Thomas Jones in the offseason, thus giving them a viable No. 1 running back. Last season, the Jets used three different starters at tailback.