Few assistant coaches in football make a bigger impact and command more respect than Steve Spagnuolo. His players have so much belief in their longtime defensive coordinator, in fact, that Kansas City Chiefs defenders commissioned, donned and began selling custom “In Spags We Trust” t-shirts amid the team's run to Super Bowl LVIII against the San Francisco 49ers.

Andy Reid's offense led by Patrick Mahomes and Travis Kelce has been the driving force behind the Chiefs' ongoing dynasty. Ahead of their historic fourth Super Bowl berth in five seasons, though, it's Kansas City's defense that's continued staking a forceful claim as one of the best units in football—and seems fully equipped to slow down Brock Purdy and the Niners' loaded offense with the Vince Lombardi Trophy on the line.

There's no debating which team holds the advantage at quarterback heading into Super Bowl LVIII. Mahomes is broadly considered the most physically gifted signal-caller in league history, and has enjoyed more team and statistical success over his first six years as a starter than Tom Brady. Purdy, meanwhile, is a worthy MVP finalist, but has been propped up throughout 2023 by Kyle Shanahan's ballyhooed offensive attack and the most talented group of skill position players in football.

Don't expect Kansas City to take Purdy lightly despite that reality, though. Spagnuolo is making sure his team knows the last pick of the 2022 NFL Draft is much more than just a “game manager” for San Francisco.

“All (people) have to do is put the tape on,” he said of Purdy on Friday, per ESPN's Jeremy Fowler. “It’s not a quarterback that’s managing.”

Chiefs, Andy Reid praise 49ers QB Brock Purdy ahead of Super Bowl LVIII

Spagnuolo isn't the only veteran Chiefs coach supremely impressed by Purdy. Reid holds the sophomore signal-caller in high esteem, too, praising Purdy for the leadership qualities he showed in college and underrated versatility of his game as a scrambler and runner.

“Listen, he’s a heck of a player,” Reid said of Purdy, per NBC Sports Bay Area. “I remember specifically one of the Saturday afternoons watching him in college and I remember the head coach saying, ‘This guy has changed our program.’ Changing a program, you know, that’s … big. And that’s what he is. He’s doing that in the National Football League.

“Last week he did as much with his legs as he did with his arm. He ran the ball well. He’s a good football player. He’s smart. He’s got a great feel for things.”

Purdy isn't Mahomes. Nobody is. Yet as he's made clear throughout a banner 2023 campaign, Purdy possesses every physical and mental attribute needed to guide a talented team to the football mountaintop. He's much closer to Jared Goff and Matt Ryan when it comes to Super Bowl quarterbacks of recent vintage than Jimmy Garoppolo, fully capable of out-dueling Mahomes on sports' brightest stage under the right team-wide and game-specific circumstances

Don't count on the Chiefs' defense struggling in Las Vegas with a coach like Spagnuolo calling the shots, though. Good thing for San Francisco that Purdy, Christian McCaffrey, Deebo Samuel, Brandon Aiyuk and George Kittle can produce great enough offense to beat good defense.