SAN DIEGO – He missed 13 games last season due to a broken ankle suffered in a Week 3 contest against the Buffalo Bills. However, San Diego Chargers running back Danny Woodhead appeared fast and healthy in offseason work. That bodes well for Philip Rivers and San Diego’s running game, which needs a boost after averaging just 3.43 yards per carry in 2014, second-worst in the NFL.

Lock: Melvin Gordon, Branden Oliver, Woodhead

Looking good: Donald Brown

On the bubble: Dreamius Smith, Jahwan Edwards.

The good: With Woodhead returning from injury and Wisconsin’s Gordon drafted in the first round, the Chargers have much better depth at the running back position. That’s good because offensive coordinator Frank Reich said a point of emphasis this offseason is establishing more balance on offense. Expect Woodhead to return to his role as the team’s third-down and red-zone running back. Gordon will be used on early downs but has proved a better pass catcher than expected, and he will be used in the passing game. The cat-quick Oliver will provide a change of pace to a glider like Gordon. And don’t forget about Brown, who struggled in his first season with San Diego. Running backs coach Ollie Wilson expects a more elusive running style from Brown, who averaged just 2.6 yards per carry in 2014.

The bad: The Chargers scored just six rushing touchdowns in 2014, so San Diego’s runners have to do a better job of getting into the end zone on a consistent basis. San Diego also had just six runs of 20-plus yards -- the explosive Gordon should help boost this statistic. Tight end/fullback David Johnson appeared in just 168 plays on offense last season. The Chargers predominantly ran three-receiver sets last season. But with Eddie Royal leaving in free agency to join the Chicago Bears, San Diego could run more two-back sets in 2015.

Bottom line: The Chargers invested in offensive linemen Orlando Franklin, Joe Barksdale and Chris Hairston in free agency with the idea of being more physical in the run game. San Diego passed the ball 57 percent of the time last season. But with the addition of Gordon, the Chargers should be closer to 50-percent passing. One thing San Diego coach Mike McCoy must do is build depth at the back end of the roster should the Chargers experience more injuries at the running back position. Rookies Smith and Edwards fit the mold of physical, downhill running backs who could prove effective in San Diego’s run scheme.