“You Can’t Run!” It wasn’t so long ago Chargers fans took pride in intimidating opposing offenses with their chants. In 2005, the Chargers defense led the NFL in stopping the run. Since then the run defense has been inconsistent. Last year, however, San Diego had a very respectable fourth best run defense. Now there are signs Chargers fans may resort to chanting, “Please Don’t Run!”

Through the first three preseason games, the Chargers run defense was ranked 27th out of 32 teams. They allowed opposing runners to average 4.6 yards per rush and have given up an average 136.3 rushing yards per game. This doesn’t mean it’s time to ring the San Diego Mission bells out of alarm. The projected starting defense has not exactly been on the field throughout the preseason.

There are concerns about how well the starting defense will play together collectively as a unit when they finally take the field together for the season opener. It is also uncertain whether backup players will be able to perform at a high enough level when called upon. While it is cliché to say that a team will be competitive if they stay healthy, it is the truth when it comes to the Chargers, especially on defense.

Going into the season there are already health concerns with both starting outside linebackers Larry English and Shaun Phillips.

English has not reached his potential as the team’s 2009 first round pick. Primarily this is because his left foot has consistently been an issue. English has had two operations on the troublesome foot including having a second screw put in this past offseason. Due to the operation, English missed the first two weeks of training camp. He now says his foot feels one hundred percent, but English missed the third preseason game with a sore knee. Keeping English healthy will be a challenge.

Phillips, who led the team with 11 sacks and appeared in his first Pro Bowl in 2010, has missed the second and third preseason games with a sore hamstring. Phillips will likely be ready for the season opener.

There have also been injury concerns within the second string at outside linebacker. A sore knee prevented Antwan Barnes from participating in practice until after the second preseason game. Travis LaBoy, a free agent from the 49ers, missed the third game with a sore knee, but LaBoy could still challenge English for a starting job.

Darryl Gamble, an undrafted free agent, has been the biggest beneficiary of all of these injuries. Gamble played with the second and third string in the first preseason game against Seattle and led the team on tackles (7 solo, 1 assist, and 1 sack). After this performance and with the injuries to the other linebackers, Gamble started and played the entire second and third games. However, Gamble was far less effective playing against the other team’s first-string. There is some doubt whether Gamble will make the final 53-man roster, although likely he will.

The inside linebacker starters are healthy and look solid. Donald Butler (third round, 2010) has been terrific throughout camp, but essentially this is his rookie season because he missed all of last season with a torn Achilles tendon he suffered in training camp a year ago. Takeo Spikes, a free agent from the 49ers, should be a solid pickup and a big edition to the defense.

English, Butler, LaBoy, Spikes

Photo Credit: Dan McLellan

Depth is where the real concerns lie at inside linebacker. Jonas Mouton (second round, 61st pick overall) has developed well throughout camp, but is an unproven rookie. The Chargers re-signed veteran Stephen Cooper late in camp, but Cooper tore his right bicep muscle completely from the bone against Dallas in the second preseason game. Cooper is trying to play with the injury, but in all likelihood will not make it through the final cuts. In anticipation of Cooper not making the team, the Chargers signed veteran Kevin Bentley. Bentley, however, is not yet in football shape.

A few unanswered questions remain on the interior of the D-line, but here things are far more positive. DE Luis Castillo has had a solid preseason and could have a great year. The biggest question is how soon DE Corey Liuget (first-round, 18th overall) will supplant Jacques Cesaire as a starter. Liuget has improved every week and his physical presence will help in putting consistent pressure on opposing quarterbacks and shutting down the run.

DT Antonio Garay continues to be physically dominating and should have another great season. Garay, however, missed the third preseason game with a sore knee.

DT Vaughn Martin is the early candidate to be the most improved player this season. Martin has recorded just one sack since he was drafted in the fourth round in 2009, yet he has won battles on the line throughout camp and this preseason leads the team with three sacks. Martin’s improvement may mean Ogemdi Nwagbuo may not make the final cut this year.

DT Cam Thomas (fifth round 2010) has been far less impressive and looks to be another year away from developing into a run stopping force, or at least a reliable backup.

Put it altogether and the Chargers have strong front-line players on defense. If healthy, they should be able to pressure the quarterback while limiting the opposing teams’ offensive running attack. The starters, however, have not played together in the preseason, so the defense enters the regular season as an unproven unit and that in itself raises concerns.

Fortunately it appears the starters will start the season healthy, hopefully they can stay that way and collectively play well together.