ATLANTA -- The Kansas City Chiefs are one of the NFL's four 3-0 teams, but it was difficult to tell in their locker room after their 22-17 win over the Atlanta Falcons on Sunday night.

Patrick Mahomes in particular sounded a little like a player whose team had lost.

"I feel like I haven't played very well and that's not a stats thing," said Mahomes, who threw a pair of touchdown passes but also had an end zone interception. "I just feel like I'm missing opportunities whenever they're out there and not throwing the ball in the exact spot I want it to be at. I'm not playing my best football and we're still getting wins, so I've got to get better to make the offense better."

The Chiefs preserved their lead in the fourth quarter with two defensive stops inside the Kansas City 15. Both times the Falcons turned the ball over on downs.

Coach Andy Reid had a slightly more cheerful assessment, but one of his postgame talking points focused on the offense putting the Chiefs in jeopardy by going three plays and out on its one drive in between the two defensive stops.

After the Falcons scored a touchdown on the opening drive, the Chiefs put together a methodical, time-consuming, 17-play drive that appeared destined to end with a score of their own. But they instead came away with nothing when Mahomes threw the end zone interception to safety Justin Simmons, a former Denver Bronco who has six career picks against Mahomes.

No other player has more than two against him.

"Those are the mistakes that you can't make in the red zone, and it seems like I make it to Simmons every time I play him," Mahomes said.

The Chiefs have emphasized getting more big plays offensively this season, but other than a 27-yard throw to Rashee Rice in the third quarter, their longest play was 17 yards.

Mahomes threw 39 passes but had just 217 yards to show for them.

"It's about me getting back to my fundamentals, putting our guys in the right position, and then we've got to execute at a higher level offensively," Mahomes said. "If teams are going to make us drive the field, we have to prove that we're able to do that, and I'm sure we'll get a lot of the same this next week with the [game against the] Chargers."