Brandon Jacobs of the New York Giants celebrates after he...

Brandon Jacobs of the New York Giants celebrates after he scored a 1-yard rushing touchdown in the second quarter against the Green Bay Packers. (Dec. 4, 2011) Credit: Getty Images

One day back and Brandon Jacobs is already moving up the depth chart.

The running back made it clear that he is here to play and not be a baby-sitter to David Wilson and the rest of the backfield. That opportunity may come more quickly -- and more abundantly -- than anyone thought when Jacobs signed Tuesday evening. Da'Rel Scott, who was Wilson's backup in the opener, had to leave Wednesday's practice early with a knee injury.

An MRI showed no structural damage for Scott, but it's unclear how much he will be able to play Sunday against the Broncos. With rookie Michael Cox the only other healthy running back on the roster and not yet ready to contribute to the offense, that leaves only two other options.

Wilson and Jacobs. The newest backfield duo.

But can they be as effective as other pairings Jacobs has been a part of with the Giants? Like when he and Derrick Ward each ran for more than 1,000 yards in 2008? Or when he and Ahmad Bradshaw split the carries for a pair of Super Bowl runs?

"We're going to do this together,'' Jacobs said. "We're teamed up and we're ready to do it.''

"Having him back in the locker room is definitely a positive thing,'' Wilson said of his new wingman, whom he met only a handful of times before Wednesday. "I look at it like he's a guy who can help the team win. One of our running backs fell down today. You never know who you might need.''

Even before Scott was injured, the plan was for Jacobs to be more of a crashing back than a Crash Davis.

"Brandon comes in at a time when the veteran running back with size is someone that can help us,'' Tom Coughlin said. "We're going to try to deal with him just like we would any player right now because, quite frankly, we need him to get ready to play. He wouldn't be here if that wasn't the case.''

That doesn't mean Jacobs can't pass a few nuggets along to Wilson. One of the first things Jacobs talked to the second-year player about was his own experience coughing the ball up against the Cowboys in the 2005 opener, Jacobs' rookie season.

"We got a chance to go up and win, I fumbled on the goal line,'' Jacobs said. "I was blessed because [Jeremy] Shockey came out and scored a touchdown. But I know what he's going through, and it's tough.''

Jacobs insisted he was humbled by last season, which was spent on the 49ers roster hardly playing and yearning to be back in New York. He admitted he might cry when he takes the field Sunday and said he was so excited to be back with the Giants that he showed up to Tuesday's workout with two big suitcases.

"[Other] guys bringing in these little suitcases,'' Jacobs said of the other free agents at the workout. "I'm like, 'I'm not going home. I'm here to stay. I'm not going anywhere.' ''

And that so-called humbled Brandon Jacobs showed just as much tenacity as he used to when he stared down a question Wednesday about whether he thinks he is ready to "pick up a blitz'' or "gain a yard or two'' in short-yardage situations.

"I think I can be as productive as any running back in the National Football League,'' he said. "That's the way I feel now. I feel fast, my [extra] weight is gone, I feel good about this opportunity I have in front of me right now.''

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