Where: Arrowhead Stadium, Kansas City, Mo. (natural grass, outdoors)
When: Sunday, 1 p.m. ET (CBS)
Spread: Ravens by 6
Forecast: Cool, 40-50s
Records: Chiefs (Overall: 1-3, AFC West 0-1); Ravens (Overall: 3-1, AFC North: 2-0)
Past results: Two most recent meetings -- Jan. 9, 2011: Ravens 30, Chiefs 7; Sept. 13, 2009: Ravens 38, Chiefs 24. Series record: Tied 3-3.
What matters: Not many believe the Chiefs have a chance to win this game -- and for good reason. The Chiefs have three rotten performances and a comeback win against the winless Saints. They have a minus-13 turnover margin, the worst in the NFL by six turnovers. The Ravens have eight takeaways this season, and they've yet to have the privilege of playing the giving Chiefs. A quarterback controversy is likely on the way. And the Ravens had three extra days to prepare. So is there any reason beyond "anything can happen on any given Sunday in the NFL" to pick the Chiefs? Well, maybe one. In the past two seasons when it has looked like the Chiefs have no chance, they decide to play good football. After an 0-3 start last year that included two clunkers in the first two weeks, they won four straight. After following that winning streak up with four straight losses, they won at Chicago. In Week 15 against the undefeated Packers, they won. And when no one gave them a chance to beat a motivated New Orleans team on the road in Week 3, the Chiefs won.
Who matters: Matt Cassel. The starting quarterback (for now) has accounted for 10 of Kansas City's 15 turnovers. For the Chiefs to have any chance to win this game, Cassel has to play mistake-free football. Cassel has been able to rack up the yards, throwing for 265 per game, but a lot of his numbers have come when the result was already decided. The Ravens give up 296 passing yards per game, ranking 29th in the league. For Cassel to have success, he'll need a big game from Dwayne Bowe. In Kansas City's playoff loss to Balitmore two seasons ago, Bowe did not have a catch. This season he has been Kansas City's most consistent player -- 25 catches for 342 yards and three touchdowns.
Key matchups: Chiefs' LBs vs. RB Ray Rice. San Diego's running backs caught nine passes for 113 yards and a touchdown last week against Kansas City. Rice is second among running backs in the NFL with 22 receptions for 174 yards. OLB Justin Houston vs. Ravens RT Kelechi Osmele . Houston has four sacks so far this season and has been Kansas City's best pass-rusher, outplaying Tamba Hali. He will get to go up against a rookie in Osmele, and Baltimore has not been outstanding protecting QB Joe Flacco, who has been sacked nine times.
Injuries of note: LB Derrick Johnson missed two days of practice this week with a groin injury. Johnson hurt his ankle in the preseason and has played hurt this year, so don't count him out. S Kendrick Lewis has yet to play with a shoulder injury and is likely out. RB Peyton Hillis (ankle) and DE Glenn Dorsey did not play last week and both did not practice this week and are likley out. DE Ropati Pitoitua, who replaced Dorsey last week and had two sacks, missed practice on Thursday. CB Brandon Flowers' bruised heel that forced him to miss the preseason and the opener kept him out of practice on Wednesday, but he practiced Thursday and should play on Sunday.
Inside stuff: If Cassel struggles Sunday, expect to see Brady Quinn. Crennel is to the point where he's willing to try something else out if Cassel does not get better.
Connections: Baltimore S Bernard Pollard spent his first three seasons in the league in Kansas City. Chiefs backup LB Edgar Jones, who plays on special teams, spent his first five years in the league with Baltimore before signing with Kansas City in training camp.
Stat you should know: Through four weeks, the Chiefs have yet to play with a lead for one second this season.
Looking ahead: The Chiefs travel to Tampa Bay next week before a bye in Week 7. They'll likely be an underdog against the Bucs and a 1-5 start could result in some changes during the bye week.
Prediction: Ravens 30, Chiefs 13
Follow Chiefs reporter C.J. Moore on Twitter @CBSChiefs and @cjmoore4.