Jeff Saturday and Ryan Clark discuss Patrick Mahomes and the impact he is having on the Chiefs as well as how talented he really is. (1:20)

KANSAS CITY, Mo. -- Brad Childress described Eric Bieniemy as a “descending veteran" when they first crossed paths in 1999 with the Philadelphia Eagles, Childress as an assistant coach and Bieniemy as a reserve running back.

Bieniemy still caught the eye of the new head coach, Andy Reid, Childress and the rest of the coaching staff and eventually made the roster for his special-teams skills.

“He understood that was his value to our team, as a special-teams guy," said Childress, who later as head coach of the Minnesota Vikings gave Bieniemy his first NFL assistant job coaching Adrian Peterson and the running backs.

“I just have a picture of him coming out on the practice field because it takes older guys longer to warm up a full hour before practice and we started out right out with special teams and he wanted to be able to go full tilt to start with. His level of detail when he prepared himself to play was incredible."

Could Eric Bieniemy be the next Andy Reid coordinator to land a head coaching job? Robin Alam/Icon Sportswire

Those same qualities, with Bieniemy as offensive coordinator of the Kansas City Chiefs, have helped the Chiefs to a fast start despite having a first-year starting quarterback in Patrick Mahomes. The Chiefs are one of the NFL’s three 3-0 teams and are leading the league in scoring at more than 39 points per game.

Oh, and Mahomes has set an NFL record with 13 touchdown passes in the first three games of a season and leads the league in passer rating.

Reid calls the offensive plays while Bieniemy helps assemble the playbook and weekly game plans and runs the offensive meetings. He’s also the voice in Mahomes’ ear through the headset on game days relaying the playcalls.

Those aren’t jobs Reid would trust to just anyone.

“[Quarterback] is a detailed position," Reid said. "... It’s very easy to go, ‘Ah, we can let that one slide.’ That’s [not] how [Bieniemy] goes about it. He’s going to make sure everything is covered. I trust him for that. I can’t be there every second. He jumps in and just takes charge and I have full confidence in him so I can go be the head coach and he can run the offense. He does a heck of a job with it.

“When he brings it, he’s bringing it and it’s every day. He doesn’t let one thing slide. ... This is him. It’s attention to detail and ‘I’m going to make sure my closet is clean and your closet better be clean, too. If not I’m going to help you clean it.'"

Bieniemy wasn’t the most skilled of players, but he lasted nine NFL seasons because of his mastery of the little things. Beyond his special-teams work, he developed into a reliable third-down back because he figured out defenses, coverages and blitzes.

He now transfers that knowledge to others.

“I take a lot of personal pride in making sure everything is dotted, T's are crossed and everything is absolute," Bieniemy said.

Chiefs running back Spencer Ware gave Bieniemy credit for helping to resurrect his career in 2015 when he joined the Chiefs after being released by Seattle. Ware went on to lead the Chiefs in rushing in 2016.

“I think the biggest thing Coach Bieniemy [brings] to our offense is his intensity," Ware said. "If you take a look at his résumé and the players he’s coached and the way they play football each and every play they get out there on the field, having an entire offense with that same mentality is pretty exciting.”

Mahomes, who has seemed unstoppable at times this season, sees Bieniemy's game-plan preparation as a big factor.

“He does not let me miss any detail of what the play is supposed to do, what the protection is supposed to be and that helps me a ton because when we get to the game everything is a little bit easier," Mahomes said.

Bieniemy, who was the Chiefs' running backs coach for five seasons before being promoted to coordinator this season, was legendary for how hard he got after Peterson during their days together with the Vikings.

“He coached Adrian Peterson as hard or harder than anybody," said Childress, who was also on the Chiefs’ staff the past five years and is now the head coach of the Atlanta Legends of the Alliance of American Football. “He was unmerciful. He was not about to let him be just a guy. Eric made sure he stepped with the right foot. He made sure he understood pass protection and how he fit into the passing scheme. For years he had just been a tailback and they handed him the ball and told him to run. Eric taught him how to play the game. He would drill down and ask him after a play, ‘What were you looking at on that run? What did the [defensive tackle] do? You can’t tell me? Then you can’t run that play if you can’t tell me.’ He would throw him out of drills for that."

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Peterson, in his 12th NFL season, is fifth in the league in rushing this season with 236 yards for Washington.

“He’ll be a good head coach one day," Peterson said. “Easily. ... It was good [being coached by him] because we were able to pick up a lot from him. I always knew he would be more than just a running backs coach.”

Reid, who believed the Chiefs would lose then-offensive coordinator Matt Nagy at the end of the season, began grooming Bieniemy last season to eventually become the coordinator.

Part of that grooming was getting Bieniemy to expand his scope from just the running backs, the running game and the backs’ involvement in the passing game. Bieniemy had some experience with that, though it didn’t go particularly well.

He was the offensive coordinator at Colorado in 2011 and 2012, but the Buffaloes won a total of just four games.

“The thing I started focusing on is just seeing the bigger picture, understanding what the quarterbacks are looking at, how they’re seeing it, what their progression is, just basically taking the big picture of everything," Bieniemy said. "Just basically taking notes from a different perspective has helped. It helped a huge amount."

Being Reid’s offensive coordinator with the Chiefs has been a golden ticket. The coordinator before Nagy, Doug Pederson, is in his third season as head coach of the Philadelphia Eagles and now a Super Bowl winner.

Bieniemy’s football background is different. Pederson and Nagy each played quarterback and were quarterback coaches for Reid before becoming coordinators.

Bieniemy, 49, is also older than Pederson was when he became a head coach (47) or than Nagy is now (40). But if the Chiefs continue to win and score points at a league-leading rate, and Mahomes continues with his MVP-level play, Bieniemy could well be Reid’s next coordinator to move on as a head coach.

“He has a great appreciation for being able to run the football and being able to take somebody’s will from them by running the football," Childress said. “The biggest growth he’ll have is he’ll have to decide what he wants to hang his hat on as far as throwing the football. But he’ll be smart enough to know what he’s got as far as talent and smart enough to know what will work."