49ers turn to rookie tackle Justin Skule to fill in for Joe Staley

SANTA CLARA - Shortly after the 49ers' most impressive win in years, a 41-17 annihilation of the Cincinnati Bengals, sober reality set in:

The 49ers' season now depends on a rookie left tackle, Justin Skule.

All-Pro tackle Joe Staley broke his fibula during the third quarter - running back Raheem Mostert kicked Staley in the shin by accident. Staley will miss the next six to eight weeks. His backup, Shon Coleman, broke his leg on Aug. 10 and will miss the entire season.

Meaning Skule, a 22-year-old sixth-round draft pick, is the best left tackle the 49ers have. He will protect Jimmy Garoppolo's blind side until November, unless the 49ers sign someone else - something they have not yet done.

“This is what you deal with in the NFL,” Kyle Shanahan said Wednesday in the 49ers' auditorium. “We wouldn't have kept Skule on our roster if we didn't think he was an NFL player. You always want to give those guys more time, because the more time they have, the better they get. But that time ran out.”

After Staley broke his leg, Skule replaced him and played the entire fourth quarter, when the 49ers ran for 58 yards and sealed the victory. “He came in and did a good job,” Shanahan said. “We were mainly running the ball at that time, but it was good to get him in a real NFL game, especially since he's going to be playing a lot.”

On Wednesday afternoon, reporters circled around Skule as he stood at his locker. He looked back at the crowd with a startled expression. “This is the first time I've had this much stuff in my face before,” Skule explained. “It's new.”

Across the locker room, second-year right tackle Mike McGlinchey watched Skule with interest. “He's got to loosen up a little bit,” McGlinchey said, grinning. “He's not as rambunctious as me and Joe.”

To be fair, McGlinchey and Staley are former first-round picks with supreme talent and confidence. Skule has a more modest background.

“He doesn't talk very much, which I like,” Shanahan said. “He's quiet, goes about his business. It's not because he's not confident. I think he studies things very well. He's very smart. I was watching him at walk-through today, and he did the game plan very well. A lot of times guys hear it Wednesday in meetings, and then they go out to walk-through and it's their first time getting a start, and they kind of freak out.”

Skule played college football at Vanderbilt, one of the best academic schools in the SEC, so he's apparently intelligent. And he was a starter for four seasons, so he's experienced for a rookie. “He got to play against a lot of good players,” Shanahan said. “Didn't always make a ton of great highlight-tape plays, but he's a guy the game wasn't too big for. He helped his team win.”

NFL.com's official scouting report of Skule praises his run-blocking. It says he “uses good landmarks in zone blocking,” and has “initial footwork and quickness to reach and seal.” Meaning he fits Shanahan's run game, which features an outside-zone-blocking scheme.

“He's very efficient in what he does,” Shanahan said. “I believe he's got the type of mind and the talent to get better.”

With Skule in the game, the 49ers should be able to run the ball effectively. But NFL.com's official scouting report criticizes Skule's ability to block during pass plays. According to the report, he “gives ground against modest bull-rush attempts.”

That's one reason the 49ers hoped not to play Skule this season - they knew he needed a year of NFL weight-training to reach his potential as a pass protector. Now, they'll have to find a way to help him during pass plays on Sunday when the 49ers host the Pittsburgh Steelers.

“When you put a rookie out there, especially someone going into his first game, you've always got to think of how to help him,” Shanahan said. “Those are things you think about all day Monday and Tuesday (while game planning).

“I know he's going to have some ups and downs, but I believe he's made of the right stuff. When you're made of the right stuff, whether you have a positive or negative experience, you can always get better from it. I'm confident in Skule. By no means will he be perfect, just like Joe isn't. But I know he'll battle and give us a chance to win.”

To help Skule against the Steelers, Shanahan can call quick passes, so the defensive ends don't have enough time to hit Garoppolo. Or, Shanahan can make Garoppolo roll out of the pocket to his right, far away from the rookie left tackle.

But Shanahan can't protect Skule the entire game. At certain points, Skule will be on his own.