SANTA CLARA – The road gets a lot more difficult for the 49ers, who sit alone in first place in the NFC West with a 4-0 record.

Not only does the level of competition increase with a trip to face the Los Angeles Rams on Sunday, but the 49ers now will be playing without starting right tackle Mike McGlinchey, who never has missed a game before now due to an injury since he began playing the sport.

The 49ers will start rookie Justin Skule at left tackle in place of six-time Pro Bowl lineman Joe Staley, who continues to recover from a broken left fibula. Now, first-year player Daniel Brunskill is slated to make his first NFL start as he takes over for McGlinchey.

McGlinchey is expected to miss four to six weeks. McGlinchey is scheduled Thursday for arthroscopic surgery on his right knee, coach Kyle Shanahan said on Wednesday.

The 49ers have no plan to make any moves on their 53-man roster as a result of the injuries McGlinchey and fullback Kyle Juszczyk sustained in the team’s 31-3 victory over the Cleveland Browns on Monday night. Juszczyk is out four to six weeks with a knee sprain.

Shanahan said the 49ers would be in the market to make a trade to bolster their roster, but there do not appear to be any reasonable trade scenarios for an offensive lineman at this point, he said. Washington team president Bruce Allen said holdout tackle Trent Williams is not on the trade market.


“Things got to be available,” Shanahan said. “You got to be able to make smart decisions. If there were a smart decision out there, we’d definitely look into it. It doesn’t seem like many are available right now.”

Veteran Sam Young will now serve as the 49ers' backup tackle, while Ben Garland will be the backup at the interior positions.

Brunskill, listed at 6-foot-5, 300 pounds, spent the past two seasons on the Atlanta Falcons practice squad after signing as an undrafted rookie from San Diego State. He converted from tight end to the offensive line while in college. Brunskill spent the spring playing for the San Diego Fleet of the now-defunct Alliance of American Football.

“That’s how the guys upstairs found him,” Shanahan said. “I didn’t know much about him until he got here in OTAs and training camp. I got to see him then and I became a believer in him.

“He was ‘No. 61’ for a while for me. Then, he became ‘Brunskill’ because he was under the radar when it started out, but he earned his spot on this team. He did a real good job.”

Brunskill now wears No. 60.

Skule is a sixth-round draft pick from Vanderbilt who held up in his first two starts at Pittsburgh and Cleveland. Now, Shanahan and the 49ers must devise a plan to provide as much help as Skule and Brunskill will need Sunday against the Rams.

The 49ers expect Brunskill to step in and not be overwhelmed with the daunting task that awaits him Los Angeles edge rushers Michael Brockers and Dante Fowler.

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In order for the 49ers' offense to make it easier on Brunskill and Skule, they can help themselves out by thriving in the run game and allowing quarterback Jimmy Garoppolo to use play-action effectively. The 49ers will also likely try to pick their spots with deeper routes with a heavier dose of quick-hitting passes underneath.

“Very similar to Skule, the game’s not too big for him,” Shanahan said. “He’s very efficient. He’s a smart player, and will get the job done and he’ll ready for the challenge on third down.”