LAS VEGAS — The defense has allowed 13 touchdowns, seven through the air. And five of them were thrown by AFC West rivals Justin Herbert of the Chargers and Denver’s Russell Wilson.

So Monday night, when the Raiders (1-3) face arguably the division’s best quarterback in the Kansas City Chiefs’ Patrick Mahomes, one unit will be facing perhaps its biggest challenge — the secondary. Kickoff is 5:25 p.m. (KLAS, Channel 8).

“He’s at such an elite status in terms of his ability to perform under pressure, make plays within the system,” Raiders defensive coordinator Patrick Graham said of Mahomes. “It’s a difficult challenge, and I think our preparation for each week, we try to attack it brand new whoever the opponent is and try to see what they do best, how can we take it away, who are they going to in certain situations?”

The Chiefs (3-1) and the wily Mahomes present many issues. For one, there’s little margin for error because the talent level of the quarterback and his pass-catchers.

Mahomes ranks seventh in the league with 1,106 yards passing and is tied for first with 11 touchdown passes, alongside Detroit’s Jared Goff and Baltimore’s Lamar Jackson. Mahomes has destroyed the Raiders; he has 2,546 yards passing in eight career games, more than he’s accumulated against any other opponent.

“He’s getting comfortable, he’s getting older, he’s getting wiser,” veteran safety Duron Harmon said about Mahomes. “He knows where he wants to go with the football. He’s doing a good job of getting the ball out quick. Even when it’s dropped back, he just knows where he wants to go with the ball. This is a young quarterback who has continued to grow year after year, game after game.”

And considering that growth, Mahomes knows which area of the Raiders’ secondary he can attack.

For instance, per Pro Football Focus, safety Johnathan Abram has allowed three touchdowns in coverage in four games against the Chiefs. Overall against Kansas City, Abram has allowed 19 receptions on 20 targets for 237 yards along with the three scores.

To his credit, though, Abram leads the secondary and ranks second on the team with 29 tackles combined.

Cornerbacks Nate Hobbs and Amik Robertson will patrol the outside and are coming in after productive performances against Russell Wilson and the Broncos.

“I think we’re very confident. We just got to fix some small things that we know we’re capable of fixing,” Robertson said. “Because a guy like Mahomes, you make a few mistakes, you might regret it at the end of the game. He’s one of the best quarterbacks in this league.”

As successful as they have been, the Chiefs respect the Raiders’ unit.

“(They’re) a group of guys that are going to get after the ball (and) that’s going to challenge you every single play,” Kansas City receiver Mecole Hardman said. “So, it’s just got to be something that we got to be ready for. We’ve got to get ready (and) we’ve got to get in on the run game. Get ready to block them guys and just make plays whenever we’ve got the chance to. They’re definitely a good group of guys, and we’re going to look forward to playing them.”

Despite a 7-1 mark against the Raiders, Mahomes is anticipating a tight battle.

“It’s a true rivalry,” he said. “We know that it doesn’t matter what the records are … it’s going to be a dog fight. … They don’t have the best record, but every game, they’ve been in the game or been leading the game at certain points.”