Colin Kaepernick may have finally gotten on track last week. Seeing his one-time favorite target return could help even more.

With Michael Crabtree expected to make his season debut, the 49ers try to further solidify their position in the playoff race Sunday against a St. Louis Rams team which is in last place but has blown out its previous two opponents.

When the Rams last visited Candlestick Park, Kaepernick took over for a concussed Alex Smith and rallied San Francisco to a 24-24 tie Nov. 11, 2012. Smith would permanently lose the starting job to Kaepernick, the dual-threat quarterback who led the 49ers to a second straight NFC West title and the Super Bowl.

He hasn't been nearly as effective through the air this season, a key reason San Francisco (7-4) trails West-leading Seattle by three games and is tied with Arizona for the second wild-card spot. His 56.7 completion percentage ranks 31st in the league, his 185.2 passing yards per game rank last among 21 quarterbacks who qualify and his 11 turnovers are five more than he had all of last year.

Kaepernick surpassed 200 yards passing just twice in 10 games entering last week but came up with his best performance since a season-opening win over Green Bay. He went 15 of 24 for 235 yards with three touchdowns and no interceptions in Monday's 27-6 victory at Washington.

"Colin, he's been taking a lot of criticism, but one thing I like about Colin, he's always hanging in there. He's always fighting through adversity," tight end Vernon Davis said. "He's one of those guys who's tough. I don't know if I've ever seen anyone as tough as Colin, not just talking about the weight room tough, but emotionally."

Though Davis had his team-high ninth TD reception last week and Anquan Boldin caught a pair, Crabtree's ongoing absence could have been playing a role in Kaepernick's inconsistent play. While Davis and Boldin have combined for 90 catches and 1,347 yards, no teammate has reached 20 receptions or 200 yards receiving.

In 11 games last year once Kaepernick took over, including the playoffs, Crabtree had 66 catches for 950 yards and nine TDs -- all more than double any other 49er.

"He's a great player. He can make a lot of plays. I think everyone knows that," Kaepernick said. "I wouldn't say a security blanket, but he is a playmaker for us."

The Rams (5-6) have found one of their own.

Rookie receiver Tavon Austin has joined Hall of Famers Jim Brown and Gale Sayers as the only players since 1940 with four touchdowns of 50-plus yards in back-to-back games. Three of those scores -- one on a 98-yard punt return -- came in a shocking 38-8 win in Indianapolis, then Austin's 65-yard TD run on the game's opening drive ignited a 42-21 rout of Chicago last Sunday.

"I've been put in some great situations so far and I'm glad I took advantage of them and I hope they keep coming," said Austin, the No. 8 overall pick in this year's draft. "Hopefully, I'll keep taking advantage of them."

The 49ers' sixth-ranked defense (311.6 yards per game) has not allowed a play of 50 or more in the past four games and has limited its last eight opponents to an average of 12.5 points.

That mostly dominant stretch began with a 35-11 win in St. Louis on Sept. 26. Kaepernick threw for two TDs, while Frank Gore ran for one and had 153 of the Niners' 219 yards rushing. Gore, whose 14 rushing touchdowns against the Rams are the most in NFL history, has been limited to 79 yards on 26 carries over the past two weeks.

St. Louis has held its last two opponents to 98 yards on 40 carries while its own ground game has continued to soar.

The Rams have rushed for an average of 189.5 yards in the past four games, including a season-best 258 last week. Undrafted rookie Benny Cunningham ran 13 times for 109 yards -- nearly doubling his career total -- and Zac Stacy added 87 on the ground before leaving with a concussion.

"We focus on it and we stuck with it and we emphasized it and it's allowed us to be successful," coach Jeff Fisher said of the rushing attack. "We're pleased with it. But you have to stay consistent with it and do it week after week."

Stacy has 620 rushing yards in seven games since becoming the starter, but his status is uncertain and that leaves open the chance Cunningham carries the workload against a 49ers defense which hasn't allowed a 100-yard rusher all season.

The Rams ran for only 18 yards on 19 attempts in the first meeting, but that was before Stacy was involved and Daryl Richardson was getting most of the carries.

St. Louis is 0-4-1 in its last five visits to San Francisco.