1. Who's going to step up with Jamaal Charles being out?

It's the million-dollar question right now for the Kansas City Chiefs.

With Charles being done for the season with a torn ACL, the next-man-up philosophy now applies to the replacement of the Chiefs most important offensive player—someone who has accounted for more than 30 percent of their total yards since 2012.

Two of the options that have experience on the field this season—Charcandrick West and Knile Davis, both offer something different.

"Knile is a big, strong, powerful back – he's a downhill runner," Chiefs offensive coordinator Doug Pederson said on Thursday. "Charcandrick gives you a little more of that shiftiness, he's a one-cut guy that can make guys miss. Both have excellent speed, I would say.

"If you had to just categorize, Knile is a good long, speed and downhill runner. Charcandrick gives you more of that lateral movement and that ability to make those guys miss."

The third option, Spencer Ware, just got promoted from the practice squad.

It's going to be interesting to watch how these three running backs are used and how they're game-planned into an offense that's been highlighted by Charles' ability for the past eight years.

2. Can the Chiefs contain Vikings RB Adrian Peterson?

The Chiefs did a pretty good job containing Matt Forte and the Chicago Bears running game last week, but things don't get any easier as they face Vikings running back Adrian Peterson on Sunday.

"Adrian [Pederson] is one of the best backs going, ever, probably," Chiefs defensive coordinator Bob Sutton said on Thursday. "A guy with great speed, really great speed. Very physical, he takes great pride in yards after contact. The speed factor, if he gets to your second or third level, it's tough – you're dealing with a guy with breakaway speed."

Sutton explained the best way to try and slow Peterson down.

"You have to do a great job of trying to slow him down in the line, not letting him have clean lanes into the second level," he explained. "The thing we've talked about is this guy demands that every player on defense thinks he's the guy involved in stopping him. As soon as you relax on the back side of the play, if he makes it through that first level and you're not at full-tilt, you have no chance."

Peterson has 43 regular season games with at least 100 yards rushing, and he's second on the active list of running backs for career yards rushing with 10,562 (Frank Gore – 11,398).

The Vikings have attempted the fewest passes of any team in the NFL this season.

Their offense isn't a secret—No. 28 is getting the ball early and often.

3. Alex Smith and the passing game

Will Alex Smith have enough time to stay upright and deliver the ball down the field? Will he accurately deliver the ball down the field when receivers are open?

These are questions that will be answered on Sunday against a very good Mike Zimmer-led defense.

"He's got them playing fast," Chiefs offensive coordinator Doug Pederson said. "Their D-ends are two of the best that we've seen already. It's a simple scheme, schematically, which allows them to play that fast. With young players you try to keep it small, keep it concise and just turn those guys loose.

"You get into third down and they'll give you a couple different looks here and there. Other than that the biggest thing I've seen on tape is how fast they play, they rally to the ball and they're opportunistic. That's a defense that's creating turnovers."

The Chiefs have allowed 22 sacks this season, which ties them for last in the NFL.

Last week against the Bears, Smith completed just 53.3 percent of his passes, including 6.03 yards per attempt, which are both season lows. He now faces a Vikings defense that's allowing 125.5 yards per game on the ground, which ranks 26th in the NFL, and 232.2 yards per game through the air, which ranks 12th in the NFL.

Despite those numbers, it'll be interesting to watch how the Vikings defense tries to attack a Charles-less Chiefs offense, which may lend itself to giving Smith the opportunity to make plays in the passing game.

LAST TIME THEY MET

4. Can the Chiefs play mistake-free football?

As a team, the Vikings have only been penalized 27 times for 224 yards this season, which ranks as the best in the NFL.  

They also haven't turned the ball over but 4 times, which also ranks among the fewest in the NFL.

Penalties and turnovers are the two easiest ways for teams to beat themselves, and the Vikings aren't going to do that—they're going to make you earn it.

If the Chiefs are going to win on Sunday, that means playing mistake-free football, which is always the goal, but is even more important when you're playing a team that isn't going to give you short fields and free passes.

5. If the Chiefs hold a late lead, can they finish?

In two of the Chiefs losses this season, they've held a lead in the fourth quarter only to ultimately fall short of winning the game.

When it comes to the offense deciding whether they're actively trying to run out the clock or trying to put more points on the board, there are a lot of variables involved.

"I think there are several factors," Pederson explained. "How well your special teams and defense is playing dictates when you have leads how your offense can play. Whether you have to stay aggressive, which in our minds it's always to stay aggressive run or pass, but just because you throw doesn't mean you're aggressive.

"If you have a lead and your defense is struggling, then you need to sustain drives, stay on the field and create first downs. If you feel like you can run it three times and punt because your defense is stuffing them then that's a different mind. There are more factors that play into those types of decisions." Let's hope the Chiefs are faced with this scenario again and things fall in their favor so they can grab their second win of the season.