Lions on NFC North; The Chiefs' last undefeated team

1) The attrition on the wide receivers in this game was shocking and clearly contributed to a tough passing day for both quarterbacks – Patrick Mahomes' passer rating was 44.4 and Brock Purdy's 36.7, both career lows. Mahomes completed just five of 12 attempts against wide receiver, including 3 of 8 against Xavier Worthy. Purdy scored just 8 of 18 on pass attempts to wide receivers. The 49ers lost their top three receivers after Deebo Samuel played only a few snaps after an illness and Brandon Aiyuk left after a serious knee injury. A lack of communication was evident everywhere – on a two-point conversion attempt late in the fourth quarter, 49ers rookie Ricky Pearsall, playing in his first game since being shot seven weeks ago, failed to turn, to pick up the ball intended for him. The Chiefs' situation is at least as unclear. Without Hollywood Brown and Rashee Rice, the Chiefs expect to lean on JuJu Smith-Schuster, who suffered a hamstring injury during the game. Despite their season-long slump on offense, the Chiefs didn't enter the game in any rush to trade a receiver. With two weeks left until the Nov. 5 trade deadline, will Smith-Schuster's health outlook change the Chiefs' calculations? Even in their depleted state, the Chiefs (leading receiver Noah Gray caught four passes for 66 yards) scored 28 points over the 49ers.

2) The Chiefs, the only undefeated team left, have the luxury of putting themselves together on offense — and by that we mean waiting for Mahomes to make magic with his arms or legs, like a certain sideline forward against whom the game was called the 49ers – because their defense keeps them in every game. On Sunday, they intercepted Purdy three times, including one each from rookies Christian Roland-Wallace and Jaden Hicks, and held the 49ers to just 2 of 11 on third-down attempts. This contributed to a lopsided time of possession that left the Chiefs allowed to be on the field ten minutes longer than the 49ers. Even with the offense as inefficient as it is now — and it's just as inefficient as it was in the Mahomes era — Steve Spagnuolo's defense resumes its role from last season: carrying the Chiefs through the season while the offense handles things controlled. The Chiefs have not allowed more than two touchdowns in any game this season. Last season ended with a Super Bowl championship, and as ugly as it looks, there's no reason to believe the Chiefs can't make a similar run this season.

3) The 49ers urgently need their stars to return. While Kyle Shanahan said the team fears Aiyuk has torn his ACL, Samuel is expected to return next week. The big question is when Christian McCaffrey can return to the field. The 49ers' inability to run the ball on Sunday (24 carries, 101 yards) put the game entirely in Purdy's hands, and against a defense as good as Kansas City's, it should be no surprise that he struggled. Next week, the 49ers face the equally desperate Dallas Cowboys and may have to play them without left tackle Trent Williams, who could be suspended after being ejected for a punch on Sunday. After their bye in Week 9, the 49ers have the Bucs, Seahawks, Packers and Bills. If there's any good news for the 49ers, it's that no one else is running away with the NFC West.