Chargers Axe Veterans Bennett, Williams

After saying goodbye to running back LaDainian Tomlinson, the San Diego Chargers began preparations Thursday to rebuild their backfield. They put a first- and third-round restricted free-agent tender on Darren Sproles, and released running back Michael Bennett and 12-year veteran defensive tackle Jamal Williams to open up more cash for free agency.

"This is a difficult time of year and the most difficult part of our job," Chargers general manager A.J. Smith said. "Jamal has been an anchor of our defense for 12 seasons. He's battled courageously at one of the most punishing positions on the field, and I respect him immensely."

Bennett, 31, had only 23 carries for 65 yards last season, but his departure leaves San Diego with Sproles as its only true tailback/running back -- and he's fair game for any team willing to match his $7.283 million offer sheet and surrender the draft picks to get him.

The Chargers initially informed Sproles last week they would let him test the market as a free agent. But interest in the speedy back and return man was keen across the NFL, and that led San Diego to reconsider its decision to gamble on losing its 2009 franchise player.

With the 28th selection in each round of April's NFL Draft, except for the sixth round -- the team traded that pick for Texans defensive end Travis Johnson -- the Chargers are widely expected to shop the first round for a versatile running back who complements quarterback Philip Rivers and fits coach Norv Turner's scheme. He must excel at pass catching and pass protection, as well as churning out yards between the tackles.

So what's next for the Chargers, who also placed the maximum one-year restricted free agent tenders on wide receivers Vincent Jackson ($3.268 million) and Malcom Floyd ($3.168 million), tackle Marcus McNeill ($3.168 million), and linebacker Shawne Merriman ($3.269 million)?

"We have a plan for the offseason," Smith said in a release issued by the team. "It's a long offseason plan and we'll have many options. We're confident we'll be able to add strong depth at all positions, including running back.

"Our intentions are to have all our tendered players back. We feel good about these players and continuity is important to us."

The Chargers also finalized a two-year contract with defensive tackle Antonio Garay, who would have become a restricted free agent. The franchise also holds exclusive negotiating rights with free agent linebacker Antawn Applewhite and fullback Mike Tolbert.

The Chargers will not be bringing back a number of unrestricted free agents, among them wide receiver Kassim Osgood, center-guard Dennis Norman and tackle Jon Runyan.

As a so-called "final eight" playoff team, San Diego may sign only one unrestricted free agent with a first-year salary of $5.807 or more. The team can then sign additional UFAs at that salary range after losing one at a comparable salary. A final eight team is permitted to sign an unlimited number of players with a first-year salary not exceeding $3.862 million.