Jacobs played with the Giants for eight of his nine seasons, winning two Super Bowls.
After a stint with the 49ers last season, he returned to the Giants after Week 1 this season and rushed for a total of 238 yards and four touchdowns in seven games.
In what turned out to be the last standout game of his career, he rushed for 106 yards and two touchdowns in a loss to Chicago on Oct. 10. He rushed the ball just 14 more times the rest of the year before ultimately landing on injured reserve and having to undergo cartilage graft surgery on his left knee.
The 31-year-old Jacobs said Monday he was unsure whether he would continue playing in the NFL, as he hadn't decided if he wanted to wear down the new cartilage in his knee. He rejoined the Giants this season so he could play a potential final season with them, as compared to signing a one-day deal.
Jacobs said if he returned in 2014, it would only be to the Giants.
"I'll only be playing here," Jacobs said Monday. "Screw all them other teams. I'm a Giant, man. I tried that already. I'm a Giant. I'm a Giant up and down. (Zero)-and-16, 16-0, 8-8, whatever you want to call it. I'm a Giant. That's what it is. That's what I take and this is the organization I love. It is what it is. I won two championships here. It's never going to be the same anywhere else."
Jacobs, a Giants fourth-round pick in 2005, played for the team from 2005-11, winning a pair of Super Bowl titles, before going to San Francisco in 2012. He played two games for the 49ers, and was suspended by the organization after criticizing it on Twitter. Jacobs said Monday he suffered an injury with the 49ers that eventually required surgery, but team doctors told him he didn't need it.
He rushed for 5,094 yards and 60 touchdowns in his career, all but 7 yards of which came with the Giants. He also hauled in four receiving touchdowns.
Jacobs is the Giants' all-time leader in rushing touchdowns, and ranks fourth in franchise history in rushing yards. He was one of the team's feistiest players, and was one of its emotional leaders.
Jacobs converted a critical fourth down in the final minutes of the fourth quarter of the Giants' 17-14 win over the New England Patriots in Super Bowl XLII, the first of his two titles.
Jacobs leaves the NFL the same day that Giants offensive coordinator Kevin Gilbride announced his retirement. Jacobs' best season came under Gilrbride's direction in 2008, when he rushed for a career-best 1,089 yards and 15 touchdowns.
Jacobs rushed for 1,000 yards twice in his career -- 2007 and '08 -- and had at least seven rushing touchdowns in five seasons.