It's gauntlet time for Trent Dilfer, for Jim Hostler, for Mike Nolan, for the offensive line, and for the defense, which has the most pressure of all.

It's early October, the 49ers are 2-2, yet it's gauntlet time.

Nobody expected the 49ers to come up on Week5 hanging on by a thread of a wisp of a fragment of a prayer, and yet here they are, dangling in the cool air with vultures circling.

I mean that literally, since large vultures were spotted in the Santa Clara sky directly above the 49ers as they practiced Thursday.

Down below, Alex Smith watched practice wearing a sling, with faint hopes of coming back from his separated shoulder in a matter of weeks, not months.

Smith's replacement, Trent Dilfer, ran the offense in practice and continued to remind you more of Steve Stenstrom than of Steve Young.

Earlier, left tackle Jonas Jennings huddled with the team chaplain and then left the complex, excused by Coach Nolan on a personal matter, which will also keep Jennings from playing Sunday against Baltimore and perhaps longer.

Add the previous losses of Vernon Davis (for a few more weeks) and Manny Lawson (for the season), and you saw a team in full Hunker-Down Mode, though it's only early October and there's a bye week coming up after Sunday.

Bye weeks don't do you much good if you're sinking and desperate already.

"I expect guys to step up and do their jobs," Nolan said after practice when asked about the accumulation of absent players. "The problem with things like that, it gives them excuses. And that's not what we're about. There's other teams that have had their injuries as well."

That means Adam Snyder goes in for Jennings on an offensive line that was woeful against Seattle last weekend and now faces the stomping Ravens defense. If you don't think the offensive line is feeling the heat, you didn't hear line coach George Warhop growl his way through a media appearance yesterday.

That means Dilfer has to play 10 times better than he did Sunday, if he's capable of summoning such a thing; that means Hostler, the offensive coordinator, has to figure out if he's up for this job.

That means the 49ers' defense can't bend, break or possibly even give up a single touchdown.

If the 49ers don't rise up over the next few weeks, the losses could come fast and demoralizing over the next month or so, and that'd be it for 2007.

So yes, Nolan knows how dramatically his team will be tested from here on out, and how desperate things could get.

But it's also good for Nolan and the 49ers in one important way: Nolan has said from the beginning that it's about the team, not about only one player, and now he has no choice but to count on several back-ups to save the day.

By the way, I sort of consider Hostler the team's back-up offensive coordinator, since Norv Turner so rudely bolted the 49ers in February and might eventually come back if the Chargers continue to regress to the Norv.

On Thursday, Nolan gave Hostler his support but also didn't say that Hostler was doing everything wonderfully, either.

My interpretation: Hostler has to get this offense going, or else.

"Believe me, Jim's busting his tail and doing an outstanding job," Nolan said. "He's facing some adversity.... He's just going to have to weather the storm. But he's going to come out of it in good shape."

The Smith issue is a bit more complicated: Nobody knows when his shoulder will be well enough to get him back into the game, and nobody wants to push Smith out there before he's ready.

That's what made the 49ers so angry about the shaky ESPN.com report late Monday that Smith was seeking a second opinion and could undergo season-ending surgery at any breathless moment.

Wrong. There will be no surgery. Famed orthopedic specialist Dr. James Andrews concurred with the 49ers staff and confirmed that with Smith on Thursday.

The 49ers were naturally peeved about any false intimation that Smith had to go around them to get a closer, more cautious take on his injury.

Smith said that, ideally, he'd like to start throwing next week and return to action Oct.21 in New York (after the bye week). But he doesn't know when he will be able to put his arm above his shoulder, forget about absorb another 300-pound squashing to the turf.

"It has nothing to do with the throwing motion," Smith said. "What they're talking about is a matter of pain.... The only danger is getting hit again and landing on it."

Yeah, that might be a danger when you play quarterback in the NFL and pass rushers are running free through your offensive line. If the 49ers get desperate, will they consider endangering their young quarterback?