ASHBURN, Va. -- One play altered the trajectory of Kyshoen Jarrett's NFL career, not to mention his life.

With 6 minutes, 32 seconds left in the first quarter of Washington's 2015 season finale at Dallas, Jarrett was a tough, rookie safety for the Redskins. The sixth-round pick from Virginia Tech had worked his way into being a part-time starter. His career was promising.

Three seconds later, he was on the ground, his right arm limp, his left leg kicking the ground in pain. His life had just changed.

Jarrett had suddenly become a 22-year-old with nerve damage in his right arm that even four years later has left him without feeling in half his arm.

The Redskins (3-12) play at the Dallas Cowboys (7-8) on Sunday (4:25 p.m. ET, Fox) in a game that matters little to them other than for draft positioning. But for Jarrett, now 26, it's a return to the scene of his last snap as a player. He agreed to become a coaching intern for Washington last season, and on Sunday, he'll continue his role as the Redskins' first-year defensive quality control coach.

"I'm still having days of difficulty accepting the road [of] no longer being able to play," he said. "The coaching isn't difficult; to accept the not playing is."

Life-changing play

Kyshoen Jarrett leaves the field after suffering the arm injury that would end his career on Jan. 3, 2016, in the season finale at Dallas. Jarrett is now a quality control coach with Washington, which plays at Dallas on Sunday in this season's finale. AP Photo/Michael Ainsworth

The injury occurred on a basic run -- Dallas' Darren McFadden took a handoff on second-and-18, running through the right side of the line. Jarrett, aligned on the other hash about 7 yards off the ball, ran over to make the tackle. With the 205-pound Jarrett in position, the 220-pound McFadden lowered his shoulder and drove into the safety's right shoulder area. Jarrett spun around, hit the ground and started writhing in pain.

"I still see myself filling, getting sealed back on the play and me tracking him and hitting the hole," Jarrett said. "That's all I get from there before everything blacks out. I don't know what I could have done different. I don't know if I could have gotten a little lower, went for the legs. I don't know if he could have gave me more shoulder than helmet. Just one of those times."

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Jarrett walked off the field, tears rolling down his face, but it took a while for him to realize how much his life had changed. Four months later, doctors at the Mayo Clinic delivered the news.

Jarrett, who is right-handed, suffered severe damage to the brachial plexus, which impacts the upper extremities. A nerve transfer, from his biceps to his deltoid muscle, wasn't able to restore full usage of his right arm -- he estimates it's at 60% usage. He said he still has feeling behind the arm, but not on the upper surface. The arm has atrophied and the nerve pain continues.

"It's a nerve injury that has put limitations [on me] since that day. I'm continuing to strive and fight to regain as much strength as possible just for every-day living."

Through it all, Jarrett leaned on lessons learned during his youth and from those close to him: his mom and brothers, his wife, Chantel -- they married within a month after the injury -- his pastor and the Redskins director of player engagement, Malcolm Blacken. There were others, too. But this group formed his foundation after the injury.

Jarrett, right, was injured after this collision with Dallas running back Darren McFadden. "I don't know what I could have done different," Jarrett said. Tim Heitman/USA Today Sports

"Looking back, man, you need a support group," Jarrett said. "You need people, whether it's a therapist or whatever the case may be. You have to talk out your emotions. Have to. That goes out to players who may have their careers ended in one year or a player who says they're making a decision to retire after 10 years."

Facing the end of a career can be jarring.

"You have this time period where you feel like, 'Who am I? What's my purpose?'" he said. "Your family has allowed you to be tunnel vision. When you have such tunnel vision and it's taken away so abruptly, it's tough. There's really no way to deal with it. You just have to go through it and accept what cards are being dealt at that time."

His mother, Vinise Capers, drilled home that lesson as she saw him develop into an undersized safety in the NFL.

"I raised him with the dynamic that they did not have permission to crumble under the expectations of society," she said.

She'd deliver that message over the phone again and again.

"Then I would hang up and bawl like a baby," she said.

Overcoming challenges

Jarrett, back left, with his brothers -- Charles Capers, back center, Charod Bridges, right, and Daishawn Capers, front left -- and his mother, Vinise Capers. Photo courtesy of Vinise Capers

Capers raised Kyshoen and three other sons -- Daishawn Capers, Charles Capers and Charod Bridges. Daishawn, 29, has cerebral palsy, cognitive disabilities and is blind. He is confined to a wheelchair. Vinise didn't accept any pity parties, and neither did Jarrett, who would cut his brother's hair while in college and still does to this day.

"He was always a little brother to him and playful," Vinise said of Jarrett. "He would lift him and help bathe him and help shower him, help dress him and transport him in and out of the vehicle before we got an ambulatory van. He was always supportive."

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Jarrett watched his mom go to school and work full time in her quest to become a certified life coach, which she achieved five years ago. She would leave every morning at 5, and when she'd come home, she would relieve the nurse who was helping with Daishawn and end her day at 11 p.m.

"And start all over again," said Vinise.

That's the same approach Jarrett followed after his injury. He'd get up, get through the day and start all over again. There were physical and mental hurdles. There were little victories. One occurred this summer when he showed up wearing short sleeve shirts to practice. Previously, he had worn long sleeves to conceal the atrophy in his right arm.

"That's definitely a win," he said. "If you see me on the field, there is no hiding. Every week, it takes a hurdle to say, 'I'm not going to cover up, and I'll be my true authentic self.'"

Many steps remain.

"When I look in the mirror, there's two different people," Jarrett said. "If I can see the differences, someone else can surely see my differences. At times and very early, self-image begins to become an issue. I went from this 205-pound guy, pretty evenly built -- I can tackle some of the strongest men without a problem -- down to a guy I feel is barely recognizable physically. At times, it was definitely a big struggle."

It reminded him of Daishawn.

"All my life, I experienced people staring at him, people wondering what is wrong," Jarrett said. "As his brother, it made me protective. It's different. And that's the hurdle you've got to get over, what other people may think or how they may see you. What matters is me and how I see myself."

Baby steps

From an early age, Jarrett, left, helped his mother care for his older brother, Daishawn, right. Photo courtesy of Vinise Capers

In a down season for the Redskins, Jarrett brings energy. He helps defensive backs warm up before games, often moving to the music playing throughout the stadium during a free moment. He still works on rehabbing his arm. With his players, he'll talk about off-the-field issues and remind them to be prepared for whatever direction life takes them. He'll occasionally do motivational-speaking engagements.

"He just helps me keep my head and helps me remember that every day is precious," Redskins safety Montae Nicholson said.

Accepting this new reality took many months and conversations before Jarrett agreed to coach.

"It took baby steps to get him back to where he needed to be from a mental standpoint," Blacken said. "He had a hard time early, but he spun this thing around. A lot of times guys tell me they want to get into coaching, but they don't want to put in the hours. Not him.

"I knew [Jarrett] was confused, but I had to let the dust clear, and I gave him time and I gave him room. ... I didn't want to push him in a direction he didn't want to go in."

The trip isn't over for Jarrett. The Redskins' staff faces numerous changes this offseason, so his coaching future remains uncertain. And there isn't a linear path to feeling better, mentally or physically, but he likes where he's at; he knows where he was; he understands the present.

"It's definitely a good feeling. But in the midst of that feeling, I still have to overcome pain daily," he said. "The pain I'm still experiencing is reminding me that your arm can no longer do what it once did. It's a reminder back to that day."

A day when Jarrett was dealt a negative and swung it back in a positive direction.