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When C.J. Spiller reported for Chiefs training camp in July, he felt fresh and healthy. For an NFL running back on the brink of 30, that was a rare feeling. In 2016, he'd started the offseason with the Saints, but a lingering knee injury slowed him in the preseason, and he was cut in September. He bounced between the Seahawks and the Jets during the regular season but didn't stick long on either team.

After signing a one-year deal with Kansas City in February, he was confident this season would be different. To offset his advancing years, he began taking even better care of his body. He had always stayed on top of his strength training and nutrition, but he realized through talking to other veterans that he needed to take extra precautions to ensure he could survive and thrive in another NFL season. He started doing a 20-minute stretching routine before he went to sleep each night. He made sure to be mindful of what he ate—and when. "I'm a realist," Spiller says. "I realize I'm not a 20-year-old who can just jump up and go." To stay sharp mentally, he opted not to bring a TV to training camp. Instead, he spent his downtime studying the playbook on his iPad and reading.

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As the season has unfolded, Spiller's mental strength has mattered more than his physical health. At Clemson, Spiller had been introduced to motivational author Jon Gordon, and he tore through two of his most popular books again in camp: The Energy Bus and Training Camp. It is those books, he says, and the hard copy of the Bible he carries with him everywhere, that have helped him stay positive throughout this season. Although it isn't unusual for a 30-year-old running back to struggle to find footing on an NFL roster, what Spiller has gone through this year is something different: He's been signed and cut four times by the same team in two months.

In August, Spiller seemed like a good bet to make the team. "He shows up to work and he's very humble," Chiefs running backs coach Eric Bieniemy told ESPN.com in a preseason story headlined "Speedy RB C.J. Spiller might be resurrecting his career with Chiefs." "He's very attentive. He does a great job of taking notes and then he comes out [to practice] and he works his tail off. He does a great job of showing the young guys how to be a professional.

"The [other] thing I would say is he can still run pretty fast."

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In three preseason appearances, Spiller rushed the ball 11 times for 46 yards and caught three passes for 21 yards. On Sept. 2, the Chiefs cut Spiller for the first time. The timing of the cut caused some head-scratching among Chiefs fans, as just a week prior fellow running back Spencer Ware had been lost for the season with a torn PCL. But the Chiefs asked Spiller to stay close and re-signed him the following day. The next couple of weeks were chaotic: The Chiefs cut Spiller again Sept. 5 and then signed him Sept. 6.

"It was a whirlwind," Spiller says now. "But every time, they were in constant communication with me and my agent. I know people on the outside were looking at it like it was crazy with the cuts and the signings, but they didn't know the background of it. I have a great appreciation for the Chiefs organization and how they've handled everything this season. They gave me an explanation every time they made a move."

When they cut him again, on Sept. 16, he decided to head home to South Carolina. For the next month, he split his time between South Carolina and Florida, where his 11-year-old daughter, Shania, lives with her mother. He enjoyed picking her up from school and watching her perform in a play. "Especially over the last eight years," he says, "I didn't get to do stuff like that too much unless it was a bye week. It was nice to be on normal dad duty."

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When in South Carolina, he stayed on a strict schedule that mirrored what he might be doing with an NFL team, with a few twists. On Monday and Tuesday mornings, his trainer guided him through pro-style workouts. On Wednesdays, he did pilates. On Thursdays, he enjoyed an off day. And then on Friday, he worked on agility drills and cardio.

On Oct. 15, Spiller was out to dinner when he heard the news that Chiefs running back Charcandrick West had suffered a concussion against the Steelers. Spiller's agent called and told him to pack a bag. The Chiefs signed Spiller the following day. "It's a long, brutal season," he says. "I'm not rooting against any guys, but it's a reality that people—especially backs—are one play away from something happening. I'm one play away from getting the call. I'm not in South Carolina to sit around and do nothing. If I wanted to just sit around, I would have told my agent to file paperwork and retired."

Spiller got two carries, totaling zero yards, on that Thursday night game against the Raiders. On Oct. 23, the Chiefs cut him for the fourth time this season. Nearly a month later, he's back in South Carolina again and awaiting the next chance. He enjoys football as much as he ever has, watching Clemson every Saturday and watching the NFL—especially the Chiefs—every Sunday. His uncle taught him the motivational formula that preparation plus opportunity equals success, and it's stuck with him. He's ready for whatever opportunity may come next.

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"Of course, I wish I was on the team playing every week," Spiller says. "Football is something I love. But I'm not going to lose confidence. I know what I can do. I want to show everyone I still have the juice. I can still get out there and run as fast as some of the best guys out there. I still have plenty of speed and quickness.

"There's a lot of football left. When the call comes, I'll be ready to rock and roll."