Ryan Matthews and Danny Woodhead are the Chargers’ running backs for Jon Beason to key on Sunday, a week after Beason made 17 tackles to help stifle the Redskins’ potent rushing attack. Beason said he has a clear goal in mind when he takes the field. “You go out there as a middle linebacker and you try to make ’em all,’’ Beason told The Post. “Sometimes it happens like that: You do your job, you’re where you’re supposed to be and you make the ones you’re supposed to make. “Having a motor, having that tempo, constantly getting after it puts you in position to make a lot of tackles. I think that’s a good characteristic of a middle ’backer.’’ Just as running backs always say they attempt to get in “a zone’’ with the ball, Beason said the same is true for a linebacker. “You try to make the first tackle, that’s the hardest one,’’ he said. “Then they kind of come in waves.’’ Running back Brandon Jacobs, listed as doubtful to play because of lingering issues with his knee, made the cross-country trip. The Giants do not take players on their road trips if there is little or no chance of them playing. Jacobs did not play last week because of the swelling in his knee and has missed four of the past six games with hamstring or knee problems. Veteran Peyton Hillis filled in for Jacobs last week and was the Giants’ most effective runner, rushing six times for 45 yards. … Cornerback Trumaine McBride (groin), listed as questionable, also made the trip. Cornerback Corey Webster (ankle) and defensive end Jason Pierre-Paul(shoulder) were declared out on Friday and did not make the trip.