SANTA CLARA -- The 49ers might unveil a new-look offense Sunday against the visiting St. Louis Rams, the first of three NFC West foes they'll face this month. Wideout Michael Crabtree is expected to make his season debut, having recovered from tearing his right Achilles in May.

"I'm really ready to play. It's a long time coming," Crabtree said Friday after completing his fourth week of practice and not appearing on the team's injury report. "I feel comfortable enough to go out there and play, go out there and see what I can do."

Asked how he felt at practice this week, Crabtree said, "I felt great, I felt real good."

The 49ers offense certainly could use his boost, but Crabtree is hesitant to "hype anything up" about his upcoming union with veteran wideout Anquan Boldin, who leads the team with 52 receptions.

"It's going to take everybody, not just me," Crabtree added. "We know where we left off from last year, and we're trying to get back there."

That would be the Super Bowl, where Crabtree was Colin Kaepernick's intended target of the 49ers' final three offensive plays in a 34-31 loss to the Baltimore Ravens.

To return to that stage, the 49ers must emerge from the tough NFC West, the NFL's equivalent to the World Cup's proverbial "Group of Death." The standings: Seattle Seahawks (10-1), 49ers (7-4), Arizona Cardinals (7-4), St. Louis Rams (5-6).

"We've got to win these. It's a playoff mentality," defensive tackle Justin Smith said. "If we lose, our window has closed or narrowed, so we've got to win."

No other division can match the NFC West's combined 29 wins. Three years ago, division teams totaled 25 combined wins, with the Seahawks and Rams finishing on top with 7-9 records.

"You're seeing a lot of balance on both sides of the football, a lot of good coaching staffs, a lot of good players," left tackle Joe Staley said. "It's a culmination of having a lot of high-draft classes for those bad years, drafting really good, talented players and bringing in good coaching staffs."

After hosting the resurgent Rams, the 49ers will greet the Seahawks for their latest chapter in arguably the NFL's hottest rivalry. Already 0-2 against the NFC South, the 49ers then play at Tampa Bay on Dec. 15 before hosting the Atlanta Falcons (Dec. 23) in Candlestick Park's likely finale. The 49ers might still be battling for a wild-card spot in Week 17, when they visit the Arizona Cardinals.

"It's only for the tough," coach Jim Harbaugh said of the upcoming schedule. "A lot of guys can play in April and May, when you're going through (organized team activities) and minicamps. A lot of guys participate in August and September.

"But there's a real toughness and a hardness of playing down the stretch, both mentally and physically.

  • Cornerback Tarell Brown is improving daily from what he called "more than bruised" ribs, caused by his touchdown-saving tackle Nov. 17 in New Orleans. Brown began running Thursday and plans to use a breathing machine one more week. He's listed as questionable for Sunday but is unlikely to play, with Tramaine Brock slated to start a second straight game.

    Brown said his rib and internal injuries came on a hit by a lineman at the end of the play. That forced him to spend the night in a New Orleans hospital after the game, then he flew home with a team doctor the next day. "Worst flight ever," Brown said.

  • Linebacker Aldon Smith was not fined for an apparently inadvertent kick Monday night into Washington quarterback Robert Griffin III's groin, the NFL said. While being blocked by Trent Williams, Smith jumped to defend a pass when his left leg hit Griffin.

    Smith has been limited by a left-shoulder injury all week and is listed as questionable. He had two sacks Monday to raise his season total to 6½.

  • Brown, defensive tackle Ray McDonald (left ankle), left guard Mike Iupati (knee) and tight end Garrett Celek (hamstring) did not practice and are listed as questionable. Also given that 50/50 designation are outside linebacker Ahmad Brooks (stinger) and wideout Quinton Patton (foot).

  • Rams leading rusher Zac Stacy passed post-concussion protocol and is cleared to play Sunday, as is the case with cornerback Trumaine Johnson and guard Chris Williams. Questionable for the Rams are guard Harvey Dahl (knee), safety T.J. McDonald (shin) and cornerback Brandon McGee (foot).

  • Fans going to Candlestick can donate and receive a commemorative pin for the American Red Cross' relief efforts in the Philippines. Pins are available Saturday at Gate 2 from 10 a.m. to 2 p.m., and on Sunday at all entrances.

  • Jerry Rice will be Sunday's honorary captain, commemorating his 1994 game against the Raiders in which he eclipsed Jim Brown's all-time touchdown record.

    For more on the 49ers, see Cam Inman's Hot Read blog at blogs.mercurynews.com/49ers.

    SUNDAY'S GAME
    St. Louis (5-6) at 49ers (7-4),
    1:05 p.m. FOX