49ers-Steelers: Five things to watch

SAN FRANCISCO -- The Pittsburgh Steelers clinched a playoff spot Sunday without even playing. The San Francisco 49ers secured one more than two weeks ago.

What these 10-3 teams are fighting for Monday night is less tangible: potential first-round bye weeks and, for San Francisco, some national validation. The 49ers stumbled to a 16-6 defeat at Baltimore in their last appearance on the national stage. They've gone 1-1 since and face a tougher-than-expected trip to Seattle next week.

With 10-3 New Orleans keeping the pressure on for the NFC's second seed, now would be a good time for the 49ers to regain their footing before they find themselves playing in the wild-card round against a hotter opponent.

Five things I'll be watching closely at Candlestick Park on Monday night:

1. The 49ers' pass protection.

San Francisco has taken more sacks in its three defeats (20) than in its 10 victories (19). Football Outsiders' Danny Tuccitto examines the disparity in his Insider piece and says the 49ers have been at their worst when their blockers outnumbered pass-rushers by two.

That seemingly illogical stat reflects opponents' ability to fool the 49ers with zone blitzes and other tactics of deception. Baltimore and Arizona succeeded in hurting San Francisco this way in recent weeks, combining for 14 sacks against the 49ers.

The Steelers, even more than the Ravens and Cardinals, have built their defensive reputation on these tactics. How well the 49ers respond will help determine how ready they are to step up their game for the postseason.

2. Ben Roethlisberger's mobility.

Players generally need multiple weeks to recover from high-ankle sprains. The Steelers' quarterback is expected to play only 11 days after suffering one against Cleveland. The injury will surely limit his mobility, providing the 49ers' defense an advantage, but how much of one?

Roethlisberger has made significant improvement as a pocket passer. Teams can no longer beat the Steelers as easily by simply keeping Roethlisberger in the pocket and forcing him to read defenses. That was Seattle's approach against a young Roethlisberger in Super Bowl XL, and it nearly worked. Roethlisberger struggled.

This season, Roethlisberger has averaged 8.5 yards per attempt from inside the pocket and 5.8 yards outside it, according to ESPN Stats & Information. That is the seventh-largest disparity of its kind among the 32 quarterbacks with enough attempts to qualify for consideration.

Keeping Roethlisberger in the pocket makes him more predictable, but not necessarily less effective.

3. Mike Wallace's deep speed.

The 49ers are doing lots of things right on defense. No team in the NFL has allowed fewer points per game this season. Every other team went into Week 15 having allowed at least five rushing touchdowns, but the 49ers had allowed none.

Defending longer passes has become a concern for the 49ers, however.

Tony Romo, Eli Manning and John Skelton exploited the 49ers' pass defense on longer throws. Overall, San Francisco has allowed more completions of at least 40 yards (11) than every team but Minnesota, New Orleans, Denver and Philadelphia.

The Steelers have eight such completions this season, tied for 13th-most in the league. Wallace has zero receptions longer than 25 yards over the Steelers' past six games, but he's still averaging 16.7 yards per catch. He beat the Cardinals deep for a 95-yard touchdown. The 49ers must be mindful of him.

4. Ted Ginn Jr. and special teams.

The 49ers have dominated opponents in field position this season. That was the case much of the way, even during their 21-19 defeat at Arizona last week. Ginn's 52-yard punt return to the Arizona 4-yard line was an example.

The Steelers rank 12th in punt coverage and 22nd in kickoff coverage, defined by yards per return allowed. Ginn should have chances to swing field position in the 49ers' favor.

The 49ers have also shown a flair for the surprise. They recovered an unexpected onside kick against the New York Giants. Only a disputed replay challenge by the Cardinals could stop the 49ers from converting a fake field goal into a long completion.

What might the 49ers have in store for the Steelers?

5. Alex Smith in the red zone.

We've gone over -- and over and over again -- the 49ers' offensive struggles inside their opponents' 20-yard line. Steve Young made a compelling point recently when he said the 49ers needed Alex Smith to create, not just run the offense, when in the red zone.

"Can you make someone take more chances when he’s not a risk-taker by nature?" the ESPN analyst and Hall of Famer told KNBR radio in San Francisco recently. "Some of the stuff they were running against Arizona was one read -- he had one option, and if that guy wasn’t open, throw it away."

The point, according to Young, was that quarterbacks must throw receivers open in the red zone because defensive backs can play tighter coverage in more confined spaces.

"We know Alex doesn’t really like to do that," Young told KNBR. "He’s not a gambler by nature. Is that something you can fix, or is that just the way it is?"

The 49ers' offense has had problems elsewhere on the field, but the team's tendency to settle for field goals has proven costly in recent weeks. San Francisco has failed to score a touchdown on all seven red zone possessions over its past three games. Its kicker, David Akers, has made four or more field goal attempts in five games, matching Olindo Mare's record since the 1970 merger.

The Steelers went through a four-game stretch this season in which opponents scored seven touchdowns on eight red zone possessions. That explains why Pittsburgh now ranks 25th in red zone touchdown percentage allowed.

The 49ers need to prevent that ranking from climbing Monday night. Whether Smith attacks the red zone problems aggressively could become a leading storyline.