GREEN BAY – Colin Kaepernick burst onto the scene in the 2012 playoffs by rushing for 181 yards in a win over the Packers. He was the hot new quarterback in the NFL, the symbol of a cutting-edge offense known as the read option.
Through three games of this season, Kaepernick's rushing average is half of what it was that January night in Candlestick Park. What's happened?
"It's like anything. Whenever anybody's had success, you study the heck out of it in the offseason. People are going to study it and work on it," Packers Defensive Coordinator Dom Capers said.
In that playoff game, the Packers got caught off guard. Kaepernick had used the read option sparingly in late-season games, but it wasn't until that playoff game the 49ers turned it loose.
"They had two weeks to prepare. They got into some looks they hadn't shown," Capers recalled.
The following year, again in the playoffs, Kaepernick made plays with his feet, including an 11-yard scramble that set up Phil Dawson's game-winning field goal. The difference in that game was "Kaepernick hurt us scrambling off the pass stuff, not out of the read option," Capers said.
Either way, the Packers know they have to keep Kaepernick in the pocket this Sunday when the Packers face the 49ers at Levi's Stadium. It's when he gets outside the pocket that he's most dangerous.
Packers.com's Mike Spofford identifies five key matchups in Sunday's Packers-49ers game.
"Every team we've played has a little zone-read element. When you go against Kaepernick, that's just part of their scheme," Capers said. "The basis of what we do starts with stopping the run."
The powerful 49ers defense of recent years has lost a lot of its parts, including Patrick Willis, Justin Smith and Aldon Smith. New Head Coach Jim Tomsula and Defensive Coordinator Eric Mangini are putting their own stamp on the 49ers defense.
"Different types of coverages, disguising coverages differently, more blitzes," Packers Associate Head Coach and offensive play-caller Tom Clements said. "We anticipate a hard game. It's a road game. I'm sure we're going to get their best shot."
The 49ers lost consecutive road games, 43-7 and 47-7, following an impressive 20-3 win over the Vikings in the opener.
"They all give great effort. Ahmad Brooks is a guy we've played against in the past. You have to beware of him," Clements added.
Australian rugby player Jarryd Hayne has caught Packers Special Teams Coordinator Ron Zook's eye. Hayne has a 37-yard punt return to his credit.
"There's no gimmick in him. He's a tough guy. He runs straight up," Zook said. "If you want to compare a group, this is Seattle. They're a carbon copy of Seattle; they run, they're tough.
"We're not close to where we need to be. This will be a test. You want to be in the top 10 in everything you do," Zook added of Packers special teams.