"Tell him to slow down," said Smith, who was the Chiefs' starter the past five seasons before he was traded to Washington in the offseason to clear the way for Mahomes. "He's making us all look bad."
Smith presumably was speaking on behalf of all the NFL's starting quarterbacks. Mahomes leads the NFL in touchdown passes with 29, six more than second-place Andrew Luck of Indianapolis. Mahomes also leads in passing yards, with 2,901.
But Smith also could have been speaking for the other 34 quarterbacks who started at least one game for the Chiefs in the team's 59-season history before Mahomes took over this year.
Mahomes, leading the 8-1 Chiefs, is already rampaging through the team's passing record book. He is two touchdown passes away from breaking the 54-year-old record for single-season touchdown passes. Len Dawson threw 30 in 1964.
Mahomes is also on pace to break Trent Green's record for single-season passing yards with one game left in the season. Green threw for 4,591 yards in 2004.
Here's what three of the best Chiefs quarterbacks of all time had to say about Mahomes as he is putting together the best QB season in team history.
Smith was teammates with Mahomes last season and had a front-row seat for Mahomes' preparation as a rookie, even though he played in just one game.
"Pat has put in the work," Smith said. "He was there so early every single day, preparing himself, learning. I think he heard that none of those Air Raid guys have been able to convert into pro guys, and he worked so hard I think to be ready for this moment. It's not by accident. Every day last year, he was in the building. They had him in there [at] 6 a.m. I told him, 'Get your sleep, too.'"
Smith had his best statistical season for the Chiefs last year, when he led the NFL in passer rating and had a career-high 26 touchdowns. Mahomes had 26 in his first eight games this season and three more in Sunday's win over the Cleveland Browns.
"Nuts, absolutely ridiculous," Smith said when asked to put Mahomes' touchdown numbers in perspective. "You could see right away the upside Pat had and not just the arm talent. I think more so it's his processing speed. He can process what he sees really fast. You knew he was going to make some wow plays. Everybody expecting he would maybe have some learning ones, too. His decision-making is so good. He's ripped ‘em when they're there, when he sees it and throws it. At the same time, when it's not there, he hasn't forced any. That's been the most impressive thing to me from afar. But the numbers? They're just absurd.
"The cool thing is that they're kind of tailoring [the playcalls] to the guy. You can certainly see how they've tweaked it with me gone and Pat stepping in, and [they're] letting it become his. They're letting him take ownership and not just running what I ran last year."
Green, the Chiefs' starting quarterback from 2001 through 2006, played on high-scoring teams coached by Dick Vermeil. But Green's Chiefs were never as strong offensively as the team is with Mahomes, and Green said he doesn't see a typical first-year starter when he watches Mahomes.
"He looks more like a seasoned guy," said Green, who as an analyst for CBS called Sunday's game against the Browns and is scheduled to work this weekend's game against the Arizona Cardinals at Arrowhead Stadium. "One of the things that stands out to me is that he'll stand in the pocket knowing he's going to get blown up, and he maintains that focus and accuracy downfield. A lot of young guys never learn to do that. He's doing it at such a young age.
"Another thing that jumps out is the way he uses his eyes. He uses his eyes quite a bit to influence defenses, and that's something that usually comes with more experience. ... He can manipulate the defenders in coverage to get them to move in a certain direction to open up a window on the back side. It usually takes time to get to a place where you're able to dictate to the defense."
Green's time with the Chiefs featured one of the NFL's best rushing games, with Priest Holmes and Larry Johnson doing a lot of scoring. Green's high with the Chiefs was 27 touchdown passes in 2004.
Like Smith, Green has an appreciation for the numbers Mahomes is posting. Green noted that the only other quarterbacks to do better than Mahomes' 26 TDs in the first eight games are Tom Brady and Peyton Manning twice.
"But those guys weren't doing it as first-year players," he said.
Dawson, who started for the Chiefs from 1962 through 1975, started more games (158) at quarterback than any other player in team history. He is the only quarterback to play the most significant portion of his career with the Chiefs and later reach the Pro Football Hall of Fame.
Dawson said he's surprised that his record has stood for 54 years but not shocked that Mahomes is the player poised to break it.
"I'm all for it," Dawson said. "It's time somebody broke that record, and it should be someone like him because he has so many tools. He has such great talent. You don't see talent like that come along very often. So he's got the tools. Then you put that with good coaching, and you're going to get a good result."
In 1964, the Chiefs were in the AFL and played a 16-game schedule. But even after the NFL went to 16 games in 1978, the Chiefs couldn't produce a quarterback who could seriously threaten Dawson's record.
Elvis Grbac, with 28 TD passes in 2000, came the closest. Dawson had 29 in 1962.
Mahomes could at long last break the record with two touchdown passes on Sunday against the Cardinals.
"This guy, from what we've seen in this short period of time, has the opportunity to break all of the records," Dawson said. "I'm not just talking about my records or Chiefs records but NFL records."