Now that the job is his to lose, let's take a look at what we should expect to see on Sunday at Edward Jones Dome in St. Louis.
Share of struggles
Kaepernick should have a decent day, but he most likely won't light up the Rams defense. St. Louis has bothered a couple really good quarterbacks this season—Matthew Stafford and Robert Griffin III.
Stafford threw three interceptions in the season opener against the Rams. Griffin III only managed 206 yards passing, one touchdown and an interception the following week.
St. Louis has the ability to get to the quarterback, especially at Edward Jones Dome. They have 31 sacks on the season and 41 tackles for loss. Also, the Rams have forced 12 interceptions, three of which were returned for touchdowns.
Kaepernick won't be going up against the New Orleans Saints defense like he did one week ago; this crew is completely different. They're young, talented and can force mistakes from quarterbacks when on top of their game.
This will be a new test for Kaepernick and the 49ers.
Kaepernick has accounted for at least one touchdown in the past three games since seeing his snaps increase following Smith's injury.
He has recorded five touchdowns in those games either through the air or on the ground.
The thing that makes Kaepernick scary is his ability to escape the pocket and make plays with his athleticism and mobility.
St. Louis' defense has rattled quarterbacks this year, most notably Matthew Stafford and Robert Griffin III, and it does so with a nice scheme and different looks.
Kaepernick doesn't have the experience of an Alex Smith, so he will have to use his ability to get out of the pocket to make plays. Sometimes when a young quarterback knows he will receive multiple looks he will tend to pull the ball down after his first option is taken away.
He may not have a great day passing the ball, but he will have a productive day on the ground.
More definitive answer to 49ers QB situation
Depending on what Kaepernick does, positive or negative, this week will give fans a better idea of what to expect from the team and how the 49ers should go moving forward.
St. Louis is a team that has the ability to give quarterbacks problems and Kaepernick is still learning how to play the position at the NFL level.
In the end, unless the 49ers win the Super Bowl, Jim Harbaugh will be wrong in one way or another. He is in a situation where he can't make the right call unless they win it all.