Keenan Allen might be the best receiver off the line, but the Chargers hope he can stay on the field

Chargers wide receiver Keenan Allen lined up across from Kansas City Pro Bowl cornerback Marcus Peters and, at the snap, threw a filthy stutter step with his left foot before planting his right and pushing back to the inside of the field.

Peters, fooled by the move, went the opposite way.

“I think he’s the best off the line in the league,” Chargers safety Jahleel Addae said. “He gets into his routes really well, precise with his movements. He and [quarterback Philip Rivers] have a good chemistry, and if he’s healthy, he’s a top five receiver.”

But a step similar to the ones that have made Allen a top NFL receiver also cost him all of last season. After dominating the Chiefs and Peters for most of the first half of last season’s opener, Allen planted that right foot and made the kind of move that’s made him one of the best.

Only this time, his right knee gave way after his anterior cruciate ligament tore.

When the Chargers play the Broncos on Monday night in Denver, it’ll have been one year since Allen’s knee injury. While the road back has been difficult — the 25-year-old receiver having to deal with mental and physical strain — Allen has proven to his teammates and himself that he’s back ready to make things difficult on the league’s corners.

“I can tell he was getting comfortable midway through [organized team activities] … Just seeing him get his confidence back and seeing him work extremely hard, even post-practice, I could tell he’s getting back at it,” Chargers cornerback Trevor Williams said. “He still has that niftiness and elusiveness. I’m excited to see him go in Week 1. ...

“He can make the tough catches. When you’re a DB and you’re covering a receiver, you can feel like you’re on him like glue. [Rivers] will put the ball where it needs to be and he’ll make that big-time catch.”

During practice Tuesday, the team’s first in their week-long build to the opener, Allen planted and juked at full speed without the cumbersome knee brace he’s worn for all but two other practices this season.

Allen said he wants to keep the brace in his locker and “just be able to go.”

Training camp was a grind, he said, as calf tightness that cost him a few days of practice could be traced to compensation for the injured right knee. But slowly, in his mind, Allen started to feel like himself.

“It took some time obviously, but the more I kept doing it, the more comfortable I got and the easier it got,” he said.

While Allen has made it look easy in limited preseason snaps, Chargers coach Anthony Lynn thinks there’s still more there.

“He’ll tell you he doesn’t believe he’s 100% yet, but I think he looks great,” Lynn said. “If he just continues to improve and get better, he really is going to do something special.”

Getting back on the field Monday will be special. It’s something Lynn and the Chargers have been working toward since the schedule was released.

And, it’s something Allen has been working toward since taking that one bad step.

“It’s just continuing the dominance I have on the football when I’m out there,” Allen said. “I want to keep that going.”

Koo news kicks in

While Younghoe Koo sat in his bed watching college football on Saturday morning, his phone rang. As a player on the roster bubble, his heart sunk.

He leaned over and saw it was just a friend, took a deep breath and went back to trying to distract himself from the gravity ahead.

By the time the roster needed to be finalized, though, Koo had learned he’d won the Chargers’ kicking job as an undrafted free agent, beating out Josh Lambo in a tight competition.

Shortly after everyone discovered that he’d won the gig, phones started to ring again.

Koo, a trick-shot master Korean immigrant who moved to the United States prior to sixth grade with as much knowledge about football as English, soon captivated football fans across the world.

The combination of an incredible trick shot he performed with some college buddies (one where he makes a field goal and backflips in the same motion), a catchy name and a unique heritage to pro football made him a bit of an overnight sensation.

He was the subject of stories and segments on television. His father, who still lives in Korea, was getting calls from reporters. His mother was too.

It was all a bit overwhelming.

So, after practice Tuesday, Koo walked up to a Chargers’ media relations staffer with a simple question: “What do I do?”

“I kind of thought about it [beforehand], but I don’t know if I expected it. I definitely gave it a thought,” Koo said. “The last time there was big attention in Korea it was for Hines Ward [whose mother was Korean]. My parents and my friends have kind of mentioned it to me, and I didn’t really know how to go about it. That’s why I asked.”

While he’s enjoying being big news, Koo knows none of it matters if he can’t keep the football between the uprights.

“That’s all fun and all, but at the end of the day I’ve got to get my mind right to do what I need. I can’t let that stuff distract me,” he said. “I look at it and it’s all good. But I’m here for one thing, and that’s to make kicks.”

Chargers help Houston

Players, coaches and staff members will work for 12 hours Wednesday in Los Angeles in an effort to donate food and supplies to the victims of Hurricane Harvey, a storm that has killed at least 60 people. The storm’s most dramatic images have come from the Houston area, where Chargers players Russell Okung and Damion Square grew up.

Okung and Square are scheduled to be joined by Joey Bosa, Hunter Henry and other players. General manager Tom Telesco, Lynn and chairman Dean Spanos also are supposed to attend.

Last week, the team announced a $500,000 donation for the storm’s victims.

The drive is scheduled from 6 a.m. to 6 p.m. at the Von’s located at 4520 Sunset Blvd. Working with the Houston Food Bank, the Chargers are asking for donations that include: canned vegetables and fruit, non-perishable items such as peanut butter and soup, bottled water, hand-held snacks, cleaning supplies and personal hygiene items.

dan.woike@latimes.com

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