Joey Bosa as a third-string DE highlights Chargers' first depth chart

SAN DIEGO – In anticipation of the preseason opener against the Tennessee Titans on Saturday, the San Diego Chargers released the team’s first depth chart on Monday.

Here are a few highlights:

Joey Bosa is third string: It’s hard to make an impact on the roster when you’re not in training camp. And since the Ohio State product remains unsigned, he’s listed as third on the depth chart at defensive end behind Darius Philon and Tenny Palepoi. Players and coaches have raved about Philon and Palepoi’s play with Bosa unavailable. But it’s hard to believe that order will not change once Bosa returns to camp.

FB Derek Watt and TE Sean McGrath listed as starters: San Diego’s sixth-round selection in this year’s draft, Watt has looked like he’s belonged from Day 1, showing good anticipation as a lead blocker and soft hands as a receiver out of the backfield. McGrath is listed as a starter over rookie Hunter Henry, likely because of his ability as a blocker. Not known for his speed, McGrath has reliable hands as a pass-catcher. It’s interesting that San Diego is using a two-tight-end, two-back formation as the team’s base set on offense.

Kellen Clemens still No. 2 QB: Keeping Clemens as the team’s No. 2 quarterback behind Philip Rivers is I believe an accurate reflection of how the backups have played. Clemens has better command of the offense than Zach Mettenberger at this point, but the LSU product has looked better the past two days. And don’t count out undrafted rookie Mike Bercovici, who performed well in the team’s controlled scrimmage at FanFest over the weekend.

James Jones third string at WR: He just arrived a few days ago and still needs to learn the offense, so it should come as no surprise that Jones is No. 3 on the depth chart at receiver behind starter Travis Benjamin and Tyrell Williams. The Chargers signed Benjamin to a lucrative deal in free agency, and Williams has been impressive in camp. At the other receiver spot, Keenan Allen, Dontrelle Inman and Javontee Herndon are the top three position players.

Branden Oliver is listed as starting kick returner: Coach Mike McCoy surprisingly used Melvin Gordon as a kicker returner in practice last week, but the Wisconsin product is listed as the team’s starting running back, and not on the depth chart at kick returner. Oliver is listed as the starter, followed by Javontee Herndon, Isaiah Burse and Deandre Reaves. Rookie sixth-round draft pick Drew Kaser is listed as the starting punter over Kasey Redfern.