The Chargers began training camp with arguably their best defensive-line depth in years.

On Saturday, they lost a key reason why.

Defensive end Tenny Palepoi was forced to exit a drill early in practice, being carted off the field. Additional testing revealed a foot fracture expected to sideline him for two months, a source said.

Palepoi earned a roster spot at last year's camp as an undrafted rookie from Utah.

He proved to be a versatile player, able to play across the line as an end or nose tackle. The 24-year-old appeared in every game as a rookie, averaging about 18 defensive snaps a week. He finished with 16 tackles on the year.

The Chargers have options on how they handle the injury. One would be to wait for Palepoi's return, a difficult proposition with the constriction of a 53-man roster. He also could be placed on injured reserve, although doing so now would expose him to waivers. Either way, the extended absence of a promising, developing player is a blow.

For the past two years, General Manager Tom Telesco has had to shop late for defensive-line depth.

On Sept. 1, 2013, he traded for Cowboys nose tackle Sean Lissemore . On Sept. 1, 2014, he signed defensive end Ricardo Mathews . The group carried more depth into camp this year after the March signing of former Broncos end Mitch Unrein . He joined a group that returned all core pieces from 2014.

Palepoi's injury came during the first padded practice of camp.

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Nuts 'n' Bolts

• When the pads come on, so do knee braces for Chargers offensive linemen. The precaution is not perfect. Trevor Robinson finished practice Saturday as the first-team center in place of Chris Watt, who suffered an apparent right knee injury in the early going. Watt was able to watch practice in seemingly good spirits. "Braces do help to an extent with certain injuries," Watt said. "They can help with ACLs and MCL injuries. But I had an MCL injury in college with a knee brace. They do help with a pile-up and things like that, but if it's going to happen, it's going to happen."

• Wide receiver Stevie Johnson has turned heads since signing in March. "Very talented," coach Mike McCoy said Saturday. "You go back and watch him in Buffalo when he had the three big years. That's what we see from him here so far. ... It was a good pick up for us."

• The Chargers will wear their powder-blue uniforms Oct. 25 against the Raiders and Nov. 22 versus the Chiefs . The latter game doubles as the Alumni Game at which LaDainian Tomlinson will be inducted into the team Ring of Honor and also have his No. 21 jersey retired.

• Nearly 2,000 fans attended each of the first two public practices at Chargers Park. On a weekend and in pads, more than 3,000 were present Saturday, the club said.