Despite being 4-0 and one of just two undefeated teams left in the NFL, the San Francisco 49ers still have some lingering doubters. That's fair. The team, after all, is seemingly limping into Southern California with an NFC West showdown against the Los Angeles Rams.

The 49ers were already without starting left tackle Joe Staley. They learned this week that they would also be without their other starting tackle, Mike McGlinchey, and only fullback, Kyle Juszczyk, for four to six weeks.

The good news is that none of these injuries were season-ending. These key players will be back down the stretch. For now, though, it makes things difficult.

ESPN insider Adam Schefter joined KNBR on Thursday morning and discussed Sunday's matchup at the Los Angeles Memorial Coliseum.

"Let me say this, it's set up for LA to win this game, I'm just telling you," Schefter said on the "Murph and Mac" show. "Now, if San Francisco goes in and wins this game, I'll be very impressed. And I like their team. I really do. This is a big-time challenge.

"If they win this game, you can start all the happy talk, and dreamy talk, and potential talk that you want because it's really valid if they can go into LA and find a way to win this game."

The 49ers still have their potent defense, which has been a relief for quarterback Jimmy Garoppolo because he hasn't had to carry the team on his back, as some expected he might. Still, Schefter knows that at some point, the 49ers signal-caller will have to carry the team to a win on his own, and wonders if this weekend might be that time.

"They need him to be good, solid, not make mistakes," Schefter said of Garoppolo, "and if you can do that, they're actually good enough in other areas to win.

"Look, at some point, Jimmy G is going to have to win a game. Maybe that's this Sunday in LA against a Rams team coming off a disappointing defeat last week against Seattle, and you're going to be coming home, it's going to be angry, and maybe this is the week Jimmy G is going to have to rally the team.

"So far, he hasn't really had to do that too much, but he's going to have to at some point, and when he does, they hope he's up for the occasion."

You can listen to the entire conversation with Schefter below.