ENGLEWOOD, Colo. -- There are seven quarterbacks in the NFL who have rushed for at least 100 yards this season.
And by the time Sunday night's game is over for the Denver Broncos, the team's defense will have faced four of them. The Broncos have already chased Seattle's Russell Wilson (221 yards rushing), Kansas City's Alex Smith (108 yards rushing) and the Jets' Geno Smith (102 yards).
And in prime time this weekend they get the rushing leader at the position in the San Francisco 49ers' Colin Kaepernick. Kaepernick leads all of the league's quarterbacks with his 242 yards rushing and is coming off a game when he also threw for 343 yards against the St. Louis Rams on Monday.
"The way he runs the ball, he's not running to get first downs, he's running to score," said Broncos quarterback Peyton Manning.
Manning doesn't often study the opposing quarterback in a game week, he's got his own issues to contend with, but Kaepernick is different. Kaepernick was a counselor at the Manning Passing Academy before Kaepernick's final season at the University of Nevada.
"I can remember having some conversations with Colin," Manning said. "I could tell he was a very intense guy that was very eager to learn and what a great start to his career. It's been fun to follow those guys that have been down there."
For the most part the Broncos have contained the running passers they have faced -- holding Alex Smith to 42 yards rushing and Geno Smith to 11 yards. The Broncos were also disciplined in their approach for much of a Week 3 loss against the Seahawks as they contained Wilson in regulation.
But Wilson got loose in overtime, rushing for 21 of his 40 yards in the game on Seattle's game-winning drive, including converting a third-and-3 and a third-and-4 with scrambles. The Broncos see Kaepernick as a different kind of challenge, not as a quarterback looking to get out of trouble when he runs, but one who is looking to crease the defense for big gains.
"He's dangerous when he's running," said Broncos cornerback Chris Harris Jr. "He's not like other quarterbacks that have been running and try to slide. He kind of runs to try to make a big play out of it."
Broncos defensive coordinator Jack Del Rio has usually chosen to answer mobile quarterbacks with more speed in the Broncos' formation, choosing to play out of the Broncos specialty looks -- even on what would traditionally be run-first downs for offenses when the Broncos would play out of their base 4-3 formation.
Against the Seahawks in Week 3, Del Rio even added rookie linebackers Lamin Barrow and Corey Nelson to the formation for the first time as the Broncos tried to keep Wilson hemmed in. The Broncos also need Von Miller and DeMarcus Ware to rush with discipline and trust in the adage the edge rusher should not go deeper in the backfield than the quarterback to keep from leaving an escape route behind.
"The good thing is we'll have our pass-rushers there, we'll have our fast guys in and he'll get his yards here and there," said Broncos defensive tackle Terrance Knighton. "It's hard to stop scrambling quarterbacks in this league, especially the guy that has the ability to throw down the field. We'll do our best to contain him, but our first focus is [49ers running back] Frank Gore."
After finishing without a sack in the season opener, which was Miller's first game action since he tore an ACL last December, Miller has been the Broncos most disruptive player with all six of his sacks in the Broncos' last four games. If he and Ware can hold the edge and keep the 49ers tackles from pushing them wide to give Kaepernick run lanes to the inside, the Broncos will have a far easier time keeping him in the pocket.
"We have to keep him where we can find him," Harris Jr. said. "A lot of it is just keeping the situations to where they favor us, force them into third-and-longs to kind of limit their choices."