For the first time in 30 years, the 49ers will enter their regular-season home opener with a 2-0 record.

Fans of the 49ers found their way to Tampa Bay and Cincinnati in Weeks 1 and 2, and were loud and boisterous in the fourth quarter of those games as the home fans filed out.

“We did a good job of making them quiet,” 49ers coach Kyle Shanahan said on 49ers Game Plan, which airs Saturday at 7 p.m. on NBC Bay Area (Ch. 3).

“We got to make sure Pittsburgh doesn’t do that to us. If we do our jobs as a team, I’m pretty confident our fans will do their job.”

The 49ers (2-0) face the Pittsburgh Steelers (0-2) at 1:25 p.m. on Sunday. Shanahan wants his team to give the fans at Levi’s Stadium something to cheer about – a rare occurrence since the club moved its home stadium to Santa Clara in 2014.

“If we play well this Sunday – when I expect us to play well – I know they’ll be loud,” Shanahan said. “I just want everyone to show up and we’ll give them something to cheer about and be as rowdy as possible because it is a huge advantage.”

Here are five key players to watch in Sunday’s game:

5. CB K’Waun Williams

There is a lot that goes into playing nickel back, and the 49ers believe there are few at the position better than K’Waun Williams because of his understanding of the position and his tackling ability.

Williams, however, is coming off a rough game against the Cincinnati Bengals, in which confusion in the secondary enabled Tyler Boyd to shake loose for 47 yards one play after the 49ers took a 7-0 lead.

 

How will the Steelers try to attack the 49ers? There could be a lot of multi-receiver sets and quick-hitting throws to JuJu Smith-Schuster from the slot to attack Williams in coverage. It’s OK for Williams to yield some of those completions, but he must keep the play in front of him and hold the gains to a minimum.

4. RB Raheem Mostert

It’s abundantly clear by now ... Raheem Mostert brings a lot more to the field than special-teams ability.

As long as Tevin Coleman remains out with a high ankle sprain, Mostert is expected to share the load with Matt Breida. Both players were outstanding in the 49ers’ 41-17 victory over the Bengals last week.

In fact, Mostert is so valuable now on offense that he saw only four snaps on special teams.

Mostert gained 83 yards rushing on 13 rushing attempts, and caught three passes for 68 yards and a 39-yard touchdown that gave the 49ers a first-quarter lead they never relinquished.

The running game is such a huge part of the 49ers’ offense, as it sets up the play-action passing game. Mostert and Breida have both shown big-play ability that makes them threats to take it the distance any time the ball is in their hands.

3. Steelers QB Mason Rudolph

Second-year quarterback Mason Rudolph takes over for Ben Roethlisberger, who is out for the season after receiving surgery on his throwing elbow. Rudolph will make his first NFL start Sunday after entering Pittsburgh’s game last week after halftime.

Rudolph completed 12 of 19 passes for 112 yards with two touchdown passes to former 49ers tight end Vance McDonald and one interception. He threw another interception on a failed two-point conversion attempt.

The 49ers’ defensive line will come at Rudolph in waves and try to pressure the Oklahoma State product into mistakes. Defensive coordinator Robert Saleh said it is to be expected that the 49ers will not get too predictable with their defensive assignments designed at confusing Rudolph.

“Whether it’s pre-snap disguise, post-snap coverage, pressure, not pressure, you go into every game trying to make sure that your looks and your disguises all keep the quarterback guessing so he has to figure it out post-snap,” Saleh said.

2. LT Justin Skule

When the 49ers selected Vanderbilt offensive tackle Justin Skule in the sixth round of the NFL draft, general manager John Lynch described him as a “scrapper.” He said Skule did not always look graceful and well-polished, but he almost always got the job done while playing in the ultra-competitive Southeastern Conference.

Six-time Pro Bowl left tackle Joe Staley is out six to eight weeks with a fractured left lower leg. Skule certainly is not guaranteed to be the starter for as long as Staley is out of action. But Skule will get the first crack at the job Sunday against the Steelers. If he plays well, there's no reason to make a change. If he struggles, the 49ers will have to look at other options.

 

Skule will be matched up primarily against Steelers outside linebacker Bud Dupree, a 2015 first-round draft pick who recorded from four to six sacks in each of his first four NFL seasons. The 49ers will use a variety of strategies to give Skule some help, but there also will be times when he must hold up one-on-one against a player with a large advantage in experience.

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1. QB Jimmy Garoppolo

As much as the 49ers want there to be a significant home-field advantage and rising decibel levels in Levi’s Stadium, there is one person above all others whose performance will determine the level of fan participation.

It’s been one year and one week since Jimmy Garoppolo took the field in front of the home fans. As Garoppolo goes, so goes the spirits of the fan base.

Garoppolo has gotten off to a solid start through two games after missing the final 13 games a year ago with a torn ACL. He completed 67.3 percent of his passes for 462 yards with four touchdowns and two interceptions in road victories at Tampa Bay and Cincinnati. His passer rating is 104.8.

Garoppolo still is working through chemistry issues with his cast of wide receivers. He should get more comfortable with the likes of Marquise Goodwin, Deebo Samuel, Dante Pettis, Richie James and Kendrick Bourne. When in doubt, he always has tight end George Kittle for those crucial third-down plays.