RB Brandon Jacobs was helped off the field after injuring his knee in San Fransisco's loss 20-to-9 loss to the Houston Texans. At the end of Jacobs' only rush of the game, Texans CB Kareem Jackson made direct contact with Jacobs' leg, causing the player to remain on the ground for a few minutes. Once returning to the sidelines, Jacobs was unable to put any weight on his leg as he made his way to the lockeroom.
According to ESPN's Adam Schefter's twitter feed, x-rays on Jacobs' knee were negative; however, he will have an MRI on Sunday. Matt Maiocco of CSN reported that 49ers head coach Jim Harbaugh has confirmed Jacobs leg/knee injury, but does not consider it to be season-ending; however the RB will be out of the lineup for an unspecified amount of time.
This is a tough break for running back who was looking to revive his career in San Francisco after five seasons with the New York Giants. The loss, whether it be short or long-term, will not have a devistating impact on the 49ers. In addition to Jacobs, SF has Frank Gore and Kendall Hunter to pick up the carries.