Here are a few things to watch on Sunday:

1. Chiefs offense inside the red zone

Heading into last week's game against the Pittsburgh Steelers, the Chiefs offense ranked No. 2 in the NFL in red zone touchdown efficiency at 67.5 percent, but after an uncharacteristic 0 for 4 performance on Sunday, the Chiefs fell to No. 7 at 61.4 percent.

"The reasons weren't the same," Chiefs coach Andy Reid said of the red zone struggles. "That's my responsibility, to make sure I'm dialing up the right things so we can get ourselves in there."

If they're going to pick up the win on Sunday, they'll need to get back to the success they've seen in the red zone for the majority of the season.

2. Philip Rivers' passing yards

The Chiefs are one of just two teams in the NFL who have not yet allowed a 300-yard passer or a 50-yard completion this season, with the other team being the Miami Dolphins.

The Chiefs currently rank No. 2 in the NFL in net passing yards against at just 200.2, and Chargers quarterback Philip Rivers ranks No. 11 in the NFL by averaging 266 yards per game.

"He's not afraid to throw the ball into tight windows," Chiefs defensive coordinator Bob Sutton said of Rivers. "I think one of the things he's done really well in the last two years was take advantage of the check down and the underneath routes probably more than he ever has. He has a big time arm and he can get a ball in, in tough situations.

"He's competitive, a very competitive guy. It's one of the things that makes him great."

The Chargers offense goes as Rivers goes, and it's an area the Chiefs defense has been exceptional in this season.

3. The scoreboard

The Chiefs' focus is taking care of business on Sunday against the Chargers, but that doesn't mean fans won't be intently watching the scores of the Cleveland-Baltimore and Jacksonville-Houston games.

If the Chiefs can get the victory and sweep the season series from the Chargers, who are in the playoffs with a win on Sunday, they'll then need Cleveland and Jacksonville to pull off the upsets on the road.

These are the scenarios that most are undoubtedly familiar with by now.

So before you head out to Arrowhead Stadium for the game on Sunday, which is also Fan Appreciation Day, make sure your phone is charged for up-to-the-second updates from those games around the league.

4. Receiver Albert Wilson continuing to make his impact

Over the past three games, undrafted rookie receiver Albert Wilson has led the Chiefs with 209 yards receiving.

With five receptions of 19 yards or more during that time, Wilson has excelled on quick screens, intermediate crossing routes and getting vertical down the field. He's shown the ability to run the full route tree and has given the Chiefs another skill position player to rely on for chunks of yards.

Wilson is creating separation from defensive backs to give Smith somewhere to deliver the football.

"He's a good young player, good route runner," Reid said earlier this week of Wilson. "He's got good strength; even though he's not really tall, he's got really good strength and quickness. And then you see him after the catch and he was a good punt returner and kick returner in college. You see his ability to kind of work in space and set up his moves."

Wilson is someone to keep an eye on Sunday against the Chargers.

5. Justin Houston's sack numbers

Justin Houston leads the NFL with 18 sacks this season, and he's just two shy of tying Derrick Thomas' franchise record of 20 back in 1990.

Reid spoke of Houston and his chase for the record this week.

"[Houston] is well deserving of this by effort and how much time he spends at it," Reid said. "You guys aren't out there after practice but he stays out another half hour after practice just working different moves and the pass game.

"The two and a half hours that he's out there, he's out there practicing his trade. So you respect that. We are all pulling for him that he can finish up. I know that's not the most important thing for him, he wants to win the game. But at the same time, he sure has done a nice job with it."

Houston has 11 multi-sack games in his four-year Chiefs career, including five games with at least three sacks. Three sacks on Sunday would give Houston the all-time league record.