Chargers are in a rush to get after Bills rookie quarterback Josh Allen

It’s no secret. The best way to rattle a rookie quarterback, especially one making his first NFL start, is to apply constant pressure, as the Chargers did last Nov. 19 when they harassed Nathan Peterman into a five-interception first half in a 54-24 blowout of Buffalo in StubHub Center.

The Chargers will face another young and relatively untested Bills quarterback in Buffalo’s New Era Field on Sunday when they line up against Josh Allen, the former Wyoming gun-slinger who replaced the struggling Peterman in last Sunday’s 47-3 loss to Baltimore and was named the starter for Week 2.

“As we’ve seen on film, he’s a guy who gets a little nervous under pressure,” Chargers defensive back Desmond King said of Allen, the seventh overall pick in April’s draft. “And once he feels pressure he likes to scramble.”

This can present another problem for the Chargers. The 6-foot-5, 237-pound Allen is quick, elusive and strong, as he showed when he escaped the grasp of Terrell Suggs, the Ravens’ 265-pound Pro-Bowl linebacker, on one run Sunday.

The attributes that have drawn comparisons, at least physically, to Philadelphia quarterback Carson Wentz are what could make corralling Allen a challenge.

“He is a big, physical guy, and you see on tape that he has the ability to run, to extend plays with his legs and get yardage,” Chargers defensive coordinator Gus Bradley said. “And he’ll do it any time. He’ll run on first and second down. They have run plays designed for him.”

The Chargers faced another young, elusive, big-armed quarterback last week in Kansas City’s Patrick Mahomes, who completed 15 of 27 passes for 256 yards and four touchdowns in the Chiefs’ 38-28 win.

Mahomes did a good job of sensing and escaping the rush, and benefited from a game plan that featured several quick slants, play-action passes and run-pass options.

The Chargers, without injured defensive end Joey Bosa, applied moderate pressure but not enough. They were credited with six quarterback hits but only one sack, when rookie Derwin James dragged down Mahomes from behind on a second-quarter safety blitz.

“One thing we could do better is disguising things to make it seem like we’re in certain coverages and actually run our pressures,” King said. “There’s not really a particular way to bring a blitz, it’s how you disguise it.”

This is one of King’s strengths. The second-year pro, who plays on virtually every passing down, had four sacks last season.

“You can see tendencies at times, but there are guys who hide their blitzes a lot, and it throws people off,” King said. “I learned that last year. I’m one of the guys who knows how to disguise a blitz. You just keep things the same as you usually do. I’m more patient rather than being anxious to go all the time, and that helps.”

Bosa, who has 23 career sacks in 28 games, has been ruled out for Sunday because of a bone bruise in his left foot. Isaac Rochell, a second-year pro out of Notre Dame, will make his second start at end.

Bradley said rookie linebacker/end Uchenna Nwosu, a second-round pick out of USC who played two defensive snaps in the opener, will play a more prominent role — at defensive end — against the Bills. The 6-2, 251-pounder’s versatility, quickness and nose for the quarterback could help counter Allen.

“Getting to the quarterback is the most exciting part of the game,” said Nwosu, who had three sacks in the preseason. “They love you if you can get to the quarterback. It’s something I’m looking forward to.”

Injury report

Bosa returned from a visit to a Green Bay foot and ankle specialist with his left foot in a cast that went up to just below his knee. The Chargers continue to list Bosa as “week to week.”

The cast is believed to have been added to provide support and to aid in healing, and is not an indication that the injury is more severe than initially diagnosed. Bosa declined to speak to reporters. Asked how he was feeling, Bosa said, “Great … immobile.”

Right tackle Joe Barksdale (knee) and cornerback Craig Mager (hamstring) were also ruled out for Sunday. Speedy wide receiver Travis Benjamin (Achilles injury) was limited in Friday’s practice, but coach Anthony Lynn expects him to play.

Henry runs

There was encouraging news regarding Hunter Henry. The star tight end, four months removed from anterior cruciate ligament surgery on his right knee, ran diagonal sprints while wearing a knee brace during Friday’s practice.

Hunter was expected to miss the entire season, but it’s beginning to look as if he could return in November or December.

“It’s so soon,” Lynn said. “I was amazed at how he looked today. He’s been doing stuff on the side all along, but today he kind of took it to another level.”

Is Lynn’s outlook for Henry beginning to change?

“The more I watch him,” Lynn said, “it definitely has.”

Miami vice

Bills fans are notoriously rowdy. Opposing team buses have been pelted with rocks and bottles. In one YouTube tailgating video, a Bills fan’s pants catch on fire after he body-slams a flaming table. His buddies douse the fire with beer.

None of this intimidates Chargers linebacker Denzel Perryman.

“I’m from Miami, man,” Perryman said. “While playing Pop Warner — true story — we actually beat this team down south and they threw rocks at our bus. So it’s all right. Beer cans, all that stuff, it’s cool. It’s going to fire me up, man.”

mike.digiovanna@latimes.com

Follow Mike DiGiovanna on Twitter @MikeDiGiovanna

UPDATES:

7:50 p.m.: This article was updated to report why Joey Bosa’s left foot was placed in a cast.

This article was originally published at 3:45 p.m.