Jacobs says he's "rotting away" in limited role

In recent days, he posted a series of photos of himself playing for the Giants — and even a picture of his two Super Bowl championship rings, side by side.

"I am on this team rotting away so why would I wanna put any pics up of anything that say niners," Jacobs said. "This is by far the worst year I ever had, I'll tell you like I told plenty others."

The 30-year-old Jacobs has five carries for 7 yards while being active for only two games with the NFC West-leading Niners (9-3-1), who beat the Miami Dolphins 27-13 on Sunday.

Jacobs — inactive again with rookie LaMichael James active for the first time — has repeatedly referred any questions about his playing time to head coach Jim Harbaugh.

On Twitter later, Jacobs said: "I don't understand why people are angry at me because I wanna do what I am paid to do, I am a competitive person, I think people should be mad if I didn't wanna play. ... As for all of my Instagram photos I don't have any niner pics, if you'll find me some pics I'll put them up."

Jacobs, hampered by a knee injury earlier this season, spends approximately 20 minutes before games punching the goal-post padding. He has said it is his way of dealing with the situation.

When asked after Sunday's game about Jacobs' comments, Harbaugh only said, "I have no comment for that."