SANTA CLARA -- Brandon Jacobs tweeted this month that he isn't suiting on up Sundays because he isn't good enough. It's unfamiliar territory for the two-time Super Bowl Champion.
REWIND: Jacobs just 'not good enough' ... right now
Jacobs carried the ball in excess of 145 times in each of his past five seasons with the New York Giants. The 30-year old signed a one-year, 1.579 million contract with the 49ers and is yet to play a single snap for his new team.
You can safely assume the lack of playing time did take some mental toll on the eight-year veteran.
"The first weeks of being healthy and practicing did (wear on me mentally)," Jacobs acknowledged. "But right now, at this point, I'm just coming out here and working hard and paying attention at meetings. I stay close to Coach Rathman and they make sure I take in all the information and take my mental reps, and that's all I can do."
The 2012 NFL trade deadline passed last Thursday without so much as a rumor that Jacobs was being shopped, and while Jacobs said he got a few calls about potential rumors, he had nothing to do with them.
While there are a number of NFL teams who would gladly employ his services -- and play him -- he didn't even contemplate the notion of requesting a trade from San Francisco.
"If you demand or request trades in this business," Jacobs explained, "you get murdered for it. I didn't even think about it. I didn't know if it was something they wanted to do or not. I didn't really care to think about it. A couple guys called me with rumors they heard, I just put it on the back burner and came to work every day."
With second-round draft pick LaMichael James in the fold, and both Frank Gore and Kendall Hunter signed through 2014, this could be Jacobs' last eight regular season games in San Francisco.
Wearing a large brace on his left knee, he insisted that his health isn't what is keeping him off the field.
"I feel really good right now," Jacobs said. "That's about all I can elaborate on, but I've been saying that for a while."
He's healthy enough, but is he "good enough" to factor into the running game? Without him, the 49ers rank first in the NFL, averaging 5.6 yards per carry and 168.6 yards per game.
"You have to talk to Coach Harbaugh," Jacobs said when asked about his second-half participation plans. "I don't care to talk about that at all. You want to know anything about that, you have to talk to coach.
"Everything with me is positive."
The second half of the 2012 season will reveal Jacobs' impact on the 49ers' offensive scheme, and whether or not he'll be able to stay positive if it's none.