Since 2009 (yes, believe it or not, that's six years ago now), Jamaal Charles has served as the face of the Kansas City Chiefs.

2009 was Charles' second season in the NFL, during which he took over the top running back spot from the incumbent Larry Johnson, who the Chiefs chose to move on from during the Week 8 bye that year.

Through the first seven weeks of that season behind Johnson, Charles had compiled 116 yards rushing and 0 touchdowns. But in nine weeks as the starter, he exploded for 1,004 yards rushing and 8 total touchdowns. He followed that season up with 1,467 yards rushing and another 8 total touchdowns in 2010.

In two seasons, Charles became Kansas City's most important player, and that was no more prevalent than in 2011, when he tore his left ACL during a Week 2 matchup against the Detroit Lions. The Chiefs split carries between Thomas Jones, Jackie Battle and Dexter McCluster for the rest of the season, but the trio couldn't compare to Charles, and the team finished 7-9, missing the playoffs.

2012 brought uncertainty on how Charles would rebound from the injury, but it was only the beginning of more success.

From 2012 to 2014, Charles ran for more than 3,800 yards, added more than 1,200 yards through the air and had 39 total touchdowns. Charles became the franchise's all-time leading rusher in 2014.

And then there was 2015.

In Kansas City's Week 5 matchup with the Chicago Bears, Charles was having another great game, rushing for 58 yards on 12 carries. That is when injury struck.

On a play that had an eerily similar feel to the 2011 injury, Charles tore his ACL, this time in his right knee. To make matters worse, the Chiefs lost the game, 18-17, on a last-minute Bears touchdown, dropping to 1-4 in the process.

Since that 2009 season, the culture and success of Kansas City football had been synonymous with the health of Jamaal Charles, so understandably, being three games under .500 and losing your without-a-doubt face of the franchise made for unsure feelings about the prospect of what 2015 could be.

That's when two virtually unknown running backs stepped out of the shadows and *changed the culture *in Kansas City.

And the beauty of it all was that they did it under the watch of Charles.

"When they got their time to shine," Charles recently explained (via NFL Network), "I told them 'You have to go out there and play like you're trying to take my job,' because that's the way I would do it if I was in their position."

The funny thing was that Charles had already done it in 2009. With Johnson out of the picture, he seized Kansas City's reins and became the franchise's rock. One would think there would be reason in that situation to not serve as a mentor; he had already lived it.

But for Charcandrick West and Spencer Ware, Charles was their biggest cheerleader along the way.

It could be easy to overlook now, but the first game without Charles didn't go so well for West. Trailing by just one score against the Minnesota Vikings, West fumbled the ball with less than 5 minutes remaining and would only finish with 33 yards on the day. The Chiefs lost, 16-10.

After the game, Charles told West to write down what he was going to do next week against the Steelers on a piece of paper.

West wrote "100 yards and a touchdown."

In the most important game of his young career, West exceeded his goal, running for 110 yards and a touchdown on 22 carries and transforming from an unknown to someone to look for on the stat sheet.

After the game, he said Charles had already sent him a congratulatory text message.

"We've known what he can do, it was just a matter of getting enough opportunities," head coach Andy Reid said in the postgame press conference. "I mentioned that after last game that he needed a few more opportunities. He got those today and you saw what he did with it."

West would go on to compile more than a 100 total yards (rushing and receiving) and at least 1 touchdown in each of Kansas City's next two wins. West pointed to Charles as his reason for his success, even going as far to say he was "honoring him" through his play.

"Being around a great person like that makes you want to be great," West said after Kansas City's 45-10 win over the Detroit Lions in London. "I just keep going out there and doing things that he would do, play like he would play."

Later in the season, Ware took West's lead, filling in for him when he was dealing with injuries. When West was held out of the Week 12 game against the Bills, Ware had the best game of his career, breaking out for 114 yards rushing and a touchdown on 19 carries.

"You thought you had what you have right now, but you're never sure until they get in and get going," Reid explained after that game of Ware. "We felt from his college time that he was a hard runner, we saw that in the preseason and during camp … He's a bigger guy, hadn't played a lot of snaps, and comes in and puts together a pretty healthy game as far as number of carries and plays for you. If there's a surprise, maybe that was it."

But even as the backs had success and the Chiefs began to win, Charles, now rehabbing, remained in their ear.

"He encourages us," Ware said during Week 14. "[Charles says] 'Don't get comfortable. Don't get contentious. Keep working and keep chopping away to get better.'"

By regular season's end, Ware and West had combined for over 1,205 total yards and 11 total touchdowns since Charles' injury, and the Chiefs won 10 games in a row to storm into the postseason.

In a tournament that saw the first Chiefs playoff win in 22 seasons, both Ware and West had a touchdown.

Jamaal Charles is a player in Kansas City that is irreplaceable. That is something we know. In an offseason during which the Chiefs face numerous roster questions, general manager John Dorsey has already been quoted in saying Charles is ahead of schedule.

Asked about his status as a player for this team, he also didn't flinch.

"The guy is an extremely talented player," Dorsey sternly said of Charles when asked, "love him to death. Love how dirty-tough he is. Yeah, he's a Chief."

No, Charles isn't replaceable, but 2015 did see a shift in the culture. For six years, the Chiefs were a team that lived and died by whether or not Charles could play. Thanks to West and Ware, that* *culture is different now.

And as for Charles? He wouldn't have it any other way.

"They had a great year," he said. "They took the team and won their first playoff game in a long time. I was excited with what they did. I'm happy for them. I hope they have a great and bright future down the road."

In an NFL world that is largely business, one where your job could be gone the next day, Charles proved in 2015 that his value stretches much further than in between the white lines. As Dorsey prefers in his players, Charles' character may even exceed his skill, and West, Ware and the Kansas City Chiefs are lucky to have him as a teammate, a mentor and a leader.