KANSAS CITY, Mo. -- The Kansas City Chiefs finished September undefeated at 3-0 because that's what they do with Patrick Mahomes as their starting quarterback.

Since Mahomes became their starter in 2018, the Chiefs are 10-0 in September. Mahomes has 32 touchdown passes (nine this season) and zero interceptions.

"I truly believe it's how we run training camp," Mahomes said in explaining his September success. "Coach [Andy] Reid puts us in these situations that are very gamelike. ... I think that's a big credit to him and our whole coaching staff, as they put us in situations in training camp that we're prepared for everything right out of the gate. Then, it's about building and keep getting better and carrying that momentum throughout the season."

The Chiefs don't exactly turn into a pumpkin in October, but they have not enjoyed nearly as much success. Mahomes is 5-3 with 18 touchdown passes but seven interceptions as a starter in October. Last season, the Chiefs lost their first two games in October, and Mahomes had the two lowest QBRs of his career in those games.

To make matters worse, the Chiefs' rescheduled game Monday at Arrowhead Stadium is against the New England Patriots (4:05 p.m. ET, CBS). Mahomes is 1-2 against New England, including a loss in October 2018.

The Chiefs know to expect the unexpected on Monday, even if the Patriots will be without starting quarterback Cam Newton, who tested positive for COVID-19, resulting in Sunday's game moving. Mahomes and the Chiefs' offense have prepared for more defensive alignments, pressures and coverages that the Patriots haven't shown before.

"Knowing and playing against the New England Patriots long enough, you always go into the game plan expecting the unexpected," offensive coordinator Eric Bieniemy said. "We want to make sure that our guys have that mindset and understand that everything we're practicing against this week, [the Patriots] may flip it. So we just need to be prepared, but we want to make sure that we're giving our guys all the different looks, all the variety of fronts that they need to see, just to make sure that they're prepared to go against it Sunday. Then, when it's all said and done, it's about us going out and executing and doing what we do best and applying our rules. That's what's going to allow us to come away with a victory."

Mahomes did a lot of his best work in last week's win over the Baltimore Ravens against the blitz. He completed 17 of 21 passes for 219 yards and three touchdowns against extra rushers.

"I think the biggest thing that we do is we prepare [for it]," Mahomes said. "It's all preparation. We really prepare for blitz coverages and different looks, different fire zones, different man blitzes. We have guys that quicken up the routes and get themselves open. Then, whenever we want to take a shot versus the blitz, I think guys do a great job of making sure that they make distinct angles where I can throw the ball into space and let them make plays. We've done a great job of that."

Mahomes has spread the ball to nine receivers in the first three games. Six players have a receiving touchdown, including fullback Anthony Sherman and offensive tackle Eric Fisher.

"He's done a nice job with that," Reid said of Mahomes. "I think he has a lot of trust in the guys, and opportunities have called to where maybe it's not the primary guy. Maybe it goes to a different receiver, and he's been able to do it and see it and do it well. So that part won't change.

"When [Bieniemy] puts everything together, he does it with the fact that he gets everybody involved. I know there's only one ball -- I mean, the guys know that, too -- but still you try to give guys an opportunity to work their strengths."