Chargers shore up run defense with addition of NT Brandon Mebane

SAN DIEGO -- A breakdown of the first week of free agency for the San Diego Chargers:

Most significant signing: The addition of Cleveland Browns free agent Travis Benjamin rightfully generated a buzz because of his playmaking ability as a returner and receiver, but the signing of former Seattle Seahawks defensive tackle Brandon Mebane could be the most impactful. The Chargers struggled to consistently stop the run last season. According to ESPN Stats & Information research, the Chargers allowed 4.7 yards per rush on first down, worst in the AFC and fourth worst in the league. Mebane was the cornerstone of a strong Seattle run defense for the past five seasons, and should help young San Diego middle linebackers Manti Te'o and Denzel Perryman run free to the football. Adding a third cornerback the caliber of Green Bay Packers free agent Casey Hayward (who has nine career interceptions) also should not go overlooked, considering how much the Chargers have struggled to take away the football.

Most significant loss: Even though he did not make many plays in 2015, losing All-Pro defensive back Eric Weddle is going to create a void in San Diego’s defense. Weddle recorded 813 tackles in his nine years with San Diego after the team selected him in the second round of the 2007 draft. That's more than twice as many tackles as the next-closest Charger (Donald Butler -- 370). Weddle essentially served as the quarterback on defense for the Chargers, getting everyone lined up pre-snap, so there will be an adjustment period while restricted free-agent signee Jahleel Addae and free-agent addition Dwight Lowery learn how to work together. However, the Chargers have been anticipating Weddle’s departure for some time, and defensive coordinator John Pagano will have a plan to fill the void left by Weddle’s absence.

Player they should have signed or still could sign: While San Diego re-signed right tackle Joe Barksdale to a four-year deal, the Chargers still have not added any players to an offensive line that struggled to create holes for Melvin Gordon and to stay healthy. General manager Tom Telesco has said that Chris Watt remains the team’s center going forward, but with the Notre Dame product’s struggles to stay healthy, the Chargers need a contingency plan. Veteran centers Stefen Wisniewski or Manuel Ramirez make some sense as free-agent pickups.

What’s next: Along with depth at center and offensive tackle, the Chargers could use a fullback, a run-blocking tight end and depth at inside linebacker. If Telesco can’t find the right price for players in free agency, he could look to the draft to fill those needs. This year’s draft also has a deep pool of talent at defensive end and defensive tackle, so look for the Chargers to add pass-rushers up front defensively in April.

Overall grade: B. The Chargers did not make a big splash in free agency, but they weren’t quiet, either. Telesco addressed specific needs with sensible signings that did not break the bank, adding impact players at receiver, defensive tackle and in the secondary. He also re-signed experienced, veteran players in tight end Antonio Gates, backup quarterback Kellen Clemens and Barksdale. The loss of Weddle will sting, but overall the Chargers earn a solid B grade for their work in free agency.