Alex Smith, Philip Rivers and RG3 put up big numbers against the Philadelphia Eagles.
There's no telling what Peyton Manning will do.
The Eagles (1-2) are allowing passing yards at an alarming rate. They've given up 1,021 yards in the air so far, an average of 323 per game. Only San Diego and Washington are worse.
With Manning and the Denver Broncos (2-0) up next, the defense has to sort out its issues quickly.
"It's a huge challenge," coach Chip Kelly said. "He's one of the all-time great quarterbacks in the history of the league, not just this season, he's done it for such a long time. He prides himself on his preparation. I think if you're a competitor, you're looking forward to it."