Brandon Jacobs was back at practice for the first time since being carted off the field on Aug. 18 in Houston after taking a helmet to the left knee. The big-bodied running back went through warm-ups and individual drills with his teammates and seemed to be moving well.
Linebacker Patrick Willis also appeared to be unhampered after suffering an ankle injury Sunday. Receiver Ted Ginn (ankle) went through individual drills with his teammates. The lone 49er who did not practice was nose tackle Isaac Sopoaga, who suffered a left knee injury in the 4th quarter. If Sopoaga can't play against the Jets, Ricky Jean Francois would step in at the position.
Practicing at a drizzly Youngstown State Wednesday, Jacobs and the running backs went through a rarely-seen ball-security drill, one that used a football tethered to a long cord. The other end of the cord was attached to a fence, and the player with the ball ran in a semicircle with the cord applying tension to the ball. The drill obviously was meant to test ball security on a team that uncharacteristically gave up two fumbles - one by Frank Gore and the other by Alex Smith -- in Sunday's loss to the Vikings.
If Jacobs is healthy, he likely would be worked into games as a short-yardage runner. Through three games, only two runners - Gore and Kendall Hunter - have taken carries for the 49ers. Gore has 45 carries for 264 yards; Hunter has 18 for 64 yards. Running back Anthony Dixon has been a mainstay on special teams; rookie LaMichael James has been inactive for every game so far this season.
-- Matt Barrows