Credit: Kelley L Cox-US PRESSWIRE

The San Francisco 49ers suffered their biggest injury of training camp and the preseason after Brandon Jacobs left the team’s 20-9 loss to the Houston Texans on Saturday with a left knee injury.  According to a league source, Jacobs’ MRI did not reveal any major knee damage.  Although he is expected to miss the rest of the preseason and it is not sure if he will be healthy enough to play in the regular season opener in three weeks.

Jim Harbaugh on Jacobs’ health,

He’s going to miss a little time. The ACL’s good. The patellla’s good. It will be some time, but we’ll see.

The outlook for Jacobs was not positive after seeing him being helped off the field by Jim Harbaugh and a trainer in the first quarter.  It was even more discouraging seeing him being carted off from the sidelines.  Although he will not likely play the rest of the preseason, it was good to hear he did not suffer a serious knee injury that would have him miss some or all of the regular season.

Jacobs will be used as the short-yardage running back in the 49ers offense this season and he needs to be on the field each game.  Otherwise, the 49ers next best option as a short-yardage running back is Anthony Dixon who is struggling to make the team as a fullback.  Frank Gore will not be used as much in short-yardage situations compared to previous seasons as the 49ers try preserving him for a full season.  Other running backs LaMichael James and Kendall Hunter are not ideal for short-yardage situations because of their short frames.  Because of this and Jacobs’ injury, it increases Dixon’s chances of making the team as a running back/fullback because of the limited options.

James was also injured in the lost to the Texans.  He actually tweaked his left ankle in the preseason win over the Vikings, but suffered a more serious injury on Saturday.  James also was taken off the sidelines on a cart.  He suffered the injury in the fourth quarter after 49ers tackle Derek Hall fell on him while blocking on a play.  As James’ body went in one direction, his ankle stayed planted when Hall fell on him.  James’ injury is not considered serious but he may miss a few days of practice.

The 49ers offense cannot afford to lose either Jacobs or James, as both will be a huge part of the offense and success of the team this season.  Before Saturday’s game, it looked like the 49ers had too many running backs and not enough roster spots.  Now, we can see why the front office decided to bring in as many talented running backs as they could.  You never know when an injury will strike nor to whom.

Credit: Kyle Terada-US PRESSWIRE

The San Francisco 49ers released an updated depth chart for their exhibition game against the Houston Texans on Saturday.  The depth chart, which is released each week for a game, gives you a good indication on who is winning the position battles at training camp.

Two interesting positions listed are at wide receiver and fullback.  On the depth chart at the No. 2 wide receiver, no joke, it lists the players as: Ted Ginn Jr.-or-Randy Moss-or-Mario Manningham.  At fullback, Bruce Miller is listed ahead of Anthony Dixon, which could indicate Jim Harbaugh is leaning towards Miller as the starter again this season.  Dixon had been playing well at training camp, but he did not make much of an impression last week in the win over the Vikings.  It’s time for Dixon to step up if he wants to make the team at fullback.

Here is the full depth chart:

OFFENSE

Wide Receiver: 15 Michael Crabtree, 10 Kyle Williams, 17 A.J. Jenkins, 13 Joe Hastings, 89 Nathan Palmer, 81 Chris Owusu

Left Tackle: 74 Joe Staley, 78 Mike Person, 65 Al Netter

Left Guard: 77 Mike Iupati, 66 Joe Looney, 60 Garrett Chisholm

Center: 59 Jonathan Goodwin, 67 Daniel Kilgore, 61 Chase Beeler, 62 Jason Slowey

Right Guard: 75 Alex Boone, 68 Leonard Davis, 71 Derek Hall

Right Tackle: 76 Anthony Davis, 69 Kenny Wiggins

Tight End: 85 Vernon Davis, 46 Delanie Walker, 88 Konrad Reuland, 40 Demarcus Dobbs, 48 Garrett Celek, 47 Kyle Nelson, 83 Joe Sawyer

Wide Receiver: 19 Ted Ginn Jr. -or- 84 Randy Moss -or- 14 Mario Manningham, 18 Brett Swain, 9 Brian Tyms, 35 Ben Hannula

Fullback: 49 Bruce Miller, 24 Anthony Dixon, 44 Cameron Bell

Running Back: 21 Frank Gore, 32 Kendall Hunter, 45 Brandon Jacobs, 23 LaMichael James, 28 Rock Cartwright

Quarterback: 11 Alex Smith, 7 Colin Kaepernick, 1 Josh Johnson, 3 Scott Tolzien

DEFENSE

Left Defensive Tackle: 91 Ray McDonald, 95 Ricky Jean Francois, 63 Tony Jerod-Eddie, 69 Patrick Butrym

Nose Tackle: 90 Isaac Sopoaga, 93 Ian Williams

Right Defensive Tackle: 94 Justin Smith, 92 Will Tukuafu, 71 Matthew Masifilo

Outside Linebacker: 55 Ahmad Brooks, 98 Parys Haralson, 44 Eric Bakhtiari, 50 Cam Johnson

Inside Linebacker: 53 NaVorro Bowman, 54 Larry Grant, 51 Joe Holland

Inside Linebacker: 52 Patrick Willis, 56 Tavares Gooden, 57 Michael Wilhoite

Outside Linebacker: 99 Aldon Smith, 98 Parys Haralson, 48 Kourtnei Brown, 41 Kenny Rowe

Left Cornerback: 22 Carlos Rogers, 26 Tramaine Brock, 20 Perrish Cox

Right Cornerback: 25 Tarell Brown, 29 Chris Culliver, 33 Anthony Mosley, 40 Deante’ Purvis

Free Safety: 38 Dashon Goldson, 27 C.J. Spillman, 23 Cory Nelms, 43 Colin Jones

Strong Safety: 31 Donte Whitner, 30 Trenton Robinson, 32 Darcel McBath, 36 Michael Thomas

SPECIAL TEAMS

Punt Returner: 19 Ted Ginn Jr., 10 Kyle Williams, 23 LaMichael James

Kickoff Returner: 19 Ted Ginn Jr., 32 Kendall Hunter, 23 LaMichael James

Punter: 4 Andy Lee

Kicker: 2 David Akers, 5 Giorgio Tavecchio

Holder: 4 Andy Lee

Long-snapper: 86 Brian Jennings, 47 Kyle Nelson