The San Francisco 49ers hope to have starting left tackle Joe Staley back in the lineup by, at the earliest, late October. Rookie Justin Skule is filling in while Staley recovers from a broken fibula suffered during the Week 2 matchup against the Cincinnati Bengals.

So how did Skule do on Sunday during the 49ers' 24-20 victory against the Pittsburgh Steelers? Other than a few scattered penalties, you might not have even known he was there, and that's a good thing.

For an offensive lineman, if you don't hear his name during a broadcast, it's a good thing. That means he is doing his job and holding his own. If you do hear his name, that typically means he's getting beat by the pass rush.

"The fact that I didn't talk about him much throughout the game, I think he did very well," head coach Kyle Shanahan explained after the game. "I've got to watch the tape and see exactly. I didn't talk about him really all day.

"I know he had those two (back-to-back) penalties, which I couldn't really tell what he did on them. Not that I was watching him either. But anytime you go through a whole game like that, and you've got a rookie starting for his first time, and the play-caller isn't bringing up his name left and right, what happened, that means he did a pretty good job."

Skule had support in his first NFL start. Whenever he headed over to the sideline, he was greeted by the injured Staley, who was ready to offer up any needed advice to the rookie.

"He has been phenomenal," Skule said of Staley after the game. "Just giving me pointers, watching film with me, doing all sorts of things, giving me little tricks that he knows, that sort of thing. I couldn't have asked for a better person to help me."

The 49ers also had a backup plan if it looked like Skule couldn't hold his own against the Steelers pass rush but never had to put that plan into place.

No one was more appreciative of Skule's effort — the entire offensive line's effort, really — than quarterback Jimmy Garoppolo. The pressure from the defense was there, and there a lot, but only officially brought Garoppolo down once for a nine-yard loss.

The 49ers offense managed 436 total yards with 26 first downs against the Steelers. It also turned the football over five times, which makes the victory even more impressive.

Garoppolo was asked about Skule's performance against the Steelers.

"He was fearless from the minute I saw him this morning," Garoppolo said. "He just had the right mindset and everything. And then, even Dan (Brunskill) got in for a snap and blocked his ass off, and he was fired up. He almost broke my hand when he high fived me, but it was awesome."

Brunskill was in the game for two of the 49ers' 79 offensive snaps after right tackle Mike McGlinchey briefly exited the game. Skule, by the way, lasted through all 79 of those snaps.

"For guys those to come in like that, I've been a rookie, I know how it is, so it's impressive," Garoppolo added.

Skule finished the game with a 59.8 grade from Pro Football Focus, likely downgraded because of the penalties but on par with his previous outing against the Bengals. By comparison, Staley graded 74.0 through two games before his injury.

Guard Laken Tomlinson, who lined up next to Skule during the game, complimented Skule after the game.

"He's the freakin' man," Tomlinson told NBC Sports Bay Area. "I am really impressed."

Skule understands it was just his first NFL start and there is still a lot more for the rookie to learn. Unless the 49ers decide to go in another direction, he'll have a chance with Staley out for an extended period.

"A lot of stuff to fix," Skule said. "Can't have those penalties, those were costly penalties at pretty bad times. I had a couple of good things, but I am going to learn from it all from the tape and move on."

The 49ers made Skule a sixth-round draft pick out of Vanderbilt in April.