JACKSONVILLE, Fla. -- He's been close to finishing with a sack since being added to the active roster from the practice squad three weeks ago.

However, things finally came together for San Diego Chargers outside linebacker Thomas Keiser against the Jacksonville Jaguars. He sacked Jaguars quarterback Chad Henne twice, part of a six-sack performance by the Chargers' defense.

Keiser also had two quarterback hurries and a pass deflection in San Diego's 24-6 win over winless Jacksonville.

With outside linebacker Jarret Johnson and inside linebacker Donald Butler out, Keiser was one of a handful of young defensive players who stepped up in the duo's absence, including edge rusher Larry English (five tackles and a sack), linebacker Andrew Gachkar (five tackles), safety Jahleel Addae (four tackles and a sack) and safety Marcus Gilchrist (four tackles, two pass deflections and an interception).

“I play with a chip on my shoulder, regardless of what is said as far as whether we're missing playmakers or not,” Keiser said. “When it comes down to it, I entered this league as an undrafted free agent. Nobody expected me to do anything. And every day I go out there, I have to live with those consequences.

“It's harder coming in that way. It's harder earning opportunities to play. And once I get on the field, I take that very seriously because it's something that was hard to earn. So I go out there and try to make plays.”

At 6-foot-4 and 260 pounds, Keiser has prototypical size for an edge rusher. He had 2.5 sacks in a preseason game this season against Arizona, so San Diego coach Mike McCoy chose to go with Keiser rather than sign a pass rusher when Dwight Freeney was placed on the injured reserve with a season-ending quadriceps tear.

San Diego veteran safety Eric Weddle said Keiser's impressive play is just another example of young players finding their way defensively for the Chargers.

“We can't feel sorry for ourselves,” Weddle said. “We always like to have our best players in there. But it's the NFL. Guys are never going to be completely healthy and it's just huge for those guys -- Thomas Keiser with two sacks, Manti (Te'o) making a few big plays, (Andrew) Gachkar getting in there and getting a week better. Larry (English) had a sack. Jahleel (Addae) had a sack coming in on the dime package.

“We had a lot of young guys stepping up, growing beyond their years because they have to. We can't wait around for them. So it's exciting, and it's definitely enjoyable to see as an older guy.”