By Sam McPherson

The NFL season is often full of strange highs and strange lows for most teams, especially those franchises struggling to find and maintain an identity after coaching and personnel turnover. Thus, the San Francisco 49ers are nothing unusual so far after looking great in Week 1 and then looking terrible in Week 2.

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As the 49ers prepare to take on the 2-0 Arizona Cardinals on Sunday in the hot desert of the Phoenix metro area, they will have to decide what kind of team they want to be on both offense and defense. While emotion may have had a big role in the team’s opening win at home, that factor was clearly lacking a week later on the road.

It Starts With Defense In San Francisco

Believe it or not, the team that gave the NFL quarterback legends Joe Montana and Steve Young has built its recent identity more on defensive prowess, and that looks like it will continue in 2015. The 49ers are currently 16th in total defense in the league, smack in the middle of the pack.

But giving up 350.5 yards per game is not the way to win consistently in the NFL. San Francisco stifled the Minnesota Vikings and their young QB in Week 1 before letting the Pittsburgh Steelers and their veteran QB rip them apart in Week 2. Stopping the run has something to do with this as well, of course, but the Cardinals have their own veteran QB ready to slice and dice the 49ers defense on Sunday if the team doesn’t learn from last week’s mistakes.

Running Game Needs Healthy Bodies

In Week 1, the San Francisco offense overcame the loss of third-down running back Reggie Bush early in the game, because primary back Carlos Hyde ran wild through the Minnesota defense. In Week 2, Hyde suffered a thigh contusion and was ineffective while in the game, and the offense struggled mightily until the game was all but over in the fourth quarter.

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Hyde should play against Arizona, but there were also some questions about a possible concussion against Pittsburgh. Needless to say, he is not at 100 percent, and Hyde may need to be much healthier than he will be in order to repeat his Week 1 efforts—which are crucial to the 49ers chances of winning in Week 3.

Kaepernick’s Future

Remember when Kaepernick took the league by storm in the latter half of the 2012 season? Yes, he was inconsistent then, too, but the brilliance he displayed at times in running the ball and throwing downfield was breathtaking. Here we are three years later, and Kaep doesn’t seem to be a very good NFL quarterback, and that lack of progress is disturbing.

His big stats in Week 2 came when the team was trailing 29-3 in the fourth quarter. He didn’t have to throw much in Week 1’s win, and when he did, Kaepernick wasn’t that impressive. He just doesn’t have the consistency required of a quarterback on a Super Bowl-caliber team. Will he ever? That is the big question we ask every week he takes the field, and this week on the road against a good defense is going to challenge Kaepernick again.

Emotion Is Too Hard To Rely On In The NFL

In Head Coach Jim Tomsula’s debut in Week 1 at home in Levi’s Stadium, the 49ers played with a lot of emotion in front of a jacked-up home crowd. The result was very good, especially on defense, where San Francisco stymied a potentially potent Vikings offense with ease. Lacking that same emotion in Week 2 against Pittsburgh on the road, the 49ers fell flat.

Needless to say, the team won’t have that home-crowd emotion on Sunday, even if a lot of S.F. fans show up to root them on against the Cardinals. Tomsula can’t rely on that rah-rah approach all season, either. The 49ers are a professional football team, and they need serious Xs and Os to win every Sunday. Tomsula and his staff got out-coached against the Steelers, and with the reigning NFL Coach of the Year on the opposite sidelines Sunday, Tomsula will be up against it again.

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Sam McPherson is a freelance writer covering baseball, football, basketball, golf, hockey and fantasy sports for CBS, AXS and Examiner. He also is an Ironman triathlete and certified triathlon coach.