ATLANTA — While an undrafted rookie running back was forced to make his first NFL start alongside Patrick Mahomes in a prime-time national game, Carson Steele had plenty of reasons to be nervous Sunday night.

But one thing was certainly unique, even sweet: He worried that his football success would distract his family and friends from his sister Kesslar’s wedding back home in Indiana?

Carson’s big day — 17 carries for 72 yards in the Chiefs’ hard-fought 22-17 win over the Falcons — was also her big day. The date was set last year, long before her brother knew he had a work conflict in the NFL. It was one thing to miss his older sister’s wedding, but another to inadvertently overshadow it.

“I told her, ‘If there’s too many people watching the game, turn the TV off,'” Steele said. “She was all for it. She went along with it.”

Steele, 21, has a larger-than-life personality — his long hair and odd weight-training skills earned him nicknames like “Fabio” and “War Horse” in college. He rushed for 1,556 yards and 14 touchdowns as a sophomore at Ball State, then transferred to UCLA last year and rushed for another 847 yards and six scores. A slow 40 time — 4.77 seconds — kept him from being drafted, and he overcame the odds to make the cut with the Chiefs.

Why did Steele play such a big role on Sunday night? It goes back to the “in sickness and in health” part with the Chiefs: Clyde Edwards-Helaire was already on the non-football sick list, and starter Isiah Pacheco broke his leg in last week’s win over the Bengals, sidelining him for at least six weeks.

That left Steele, who made the Chiefs’ 53-man roster largely as a special-teams player, veteran Samaje Perine and third-year back Keaontay Ingram. Steele knew he’d have a bigger role, but he didn’t know how big a part of the Chiefs’ offense he’d be.

Steele and Perine each had six carries in the first half — Steele rushed for 26 yards, Perine for 25 — but in the second half, with the Falcons initially trailing 14-13, Steele got it all. His 17 carries ended up being the most for an undrafted Chiefs rookie in the Super Bowl era, and on a night when Mahomes wasn’t as productive as he often is, Steele helped move the chains and keep Kansas City’s offense on the field.

“I was a little nervous, that’s for sure,” he said. “I just had to relax. This is the game I’ve played my whole life. It was really special. I had to make those first few hits, relax and get into it.”

As it turned out, the calming voice that helped him mentally prepare himself all week was his sister. Both had life-changing events ahead of them, and she helped Carson find a balance between focus and excitement for a huge challenge ahead.

“She had a busy week, so we talked back and forth,” he said. “She reassured me about things, and my parents talked to me, too. When we went into this, we had no idea what was going to happen, but it was just that next-man-up mentality.”

Steele had earned the roster spot with his strong preseason performances, but that often came against reserve players and players unlikely to make the final rosters. He had played just 19 offensive snaps in the Chiefs’ first two victories, but through summer workouts and training camp he had already earned a reputation among his teammates as a hard-working player.

“He’s done a great job for us,” Pro Bowl center Creed Humphrey said after the game. “He’s a very talented player. He’s going to continue to improve and it’s great to watch him. He works really hard at this, studies really well and he’s done a great job. He’s prepared so well that when his name is called, he’ll be ready.”

The Chiefs need Steele for much more than just Sunday night. With Pacheco sidelined for a while, Steele is positioned to be their primary ball carrier. Only four undrafted rookies in the past 60 years have rushed for 1,000 yards: Dominic Rhodes of the Colts in 2001, LeGarrette Blount of the Bucs in 2010, Phillip Lindsay of the Broncos in 2018 and James Robinson of the Jaguars in 2020. The Chiefs’ record for an undrafted rookie rushing is 576 yards, set by Mack Lee Hill in 1964.

On Sunday night, video footage from Indiana showed his sister’s wedding reception. Everyone was watching the game and cheering every time Steele appeared on screen.

Now the entire family, including his sister and new brother-in-law, can relax and enjoy his success as he pursues his own ring.

“It’s really amazing,” he said of their special day together Sunday. “We came up with the W, and she went into the competition as an unmarried woman and came out married. I’m so blessed and happy for her.”

Greg Auman is an NFL reporter for FOX Sports. He previously spent a decade covering the Pirates for the Tampa Bay Times and The Athletic. You can follow him on Twitter at @gregauman.

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