St. Louis Rams - San Francisco 49ers: Under The Radar

Unless something really spectacular happens to the post season picture, this will be the final time the St. Louis Rams and San Francisco 49ers face off in Candlestick Park. It will be onto a new stage for the 49ers, playing their home games in Santa Clara in the new Levi's Stadium. Denim will be everywhere...

In the second contest between these two teams in 2013 - the first one we'll just forget about, OK? - the Rams travel to that city by the bay. Both the Rams and 49ers have morphed since their first meeting. The Rams can now run the ball, and the 49ers can throw it. Both defenses are strong, and they'll play a pivotal role in the game Sunday. But which players will rise to the occasion? "Under the radar", "Sleeper", and "Who the hell is that guy?" will be uttered more than a few times if a unlikely hero rises up and shines during this game.

I'm joined by Dave Fucillo from Niner Nation - the SBNation site for all things San Francisco 49ers. We'll be giving you our takes on which players to keep an eye on this Sunday. First up, let's look at the offensive side of the ball:

49ers offense

The 49ers passing game has struggled to get on track much of the season. Anquan Boldin and Vernon Davis have been the primary play makers. The 49ers are getting Michael Crabtree back this week, although we don't know yet what his status is for Sunday's game. At this point, the key to expanding the 49ers passing attack is Mario Manningham.

While Manningham is a fairly well-known receiver, he is still a guy who manages to fly under the radar. He tore two knee ligaments in Week 16 last season, and opened the 2013 season on the PUP list. He returned in Week 10, and the team has worked him back into the game plan. On Monday against Washington, Manningham had four catches for 45 yards. It was not a dominant display, but his shorter work opened up Anquan Boldin, setting up his two catches that resulted in the team's first touchdown. Without knowing what the team has planned with Colin Kaepernick, look for Kap to target Manningham early.

Rams Offense

Back up quarterbacks usually mean diminished offensive play-calling options. Not so with Kellen Clemens, whose been with the Rams for a few years now. He knows the offense, having been around Rams' offensive coordinator Brian Schottenheimer since their "Big Apple" days with the Jets. The only trouble with #2 QBs, is their reliability factor. There's a reason why they aren't starters in the NFL on a regular basis. Clemens has acquitted himself since Bradford went down with an ACL injury, but he'll have a jury ready to throw their thumbs down at the merest hint of stumbling. To keep this from happening, he'll need one thing, and one thing only: The Rams offensive line to play well.

This unit was put together as a "pass protection" group, but its shifted into a run blocking machine. It's widely held offensive linemen would rather run block than pass protect. This seems to be true for the Rams line. Jake Long has had trouble with elite pass rushers. With "legal-limbo" Aldon Smith across from him this Sunday, things aren't going to improve for the former Miami Pro Bowl tackle. The guard situation for the Rams is tentative at best, with Rodger Saffold surprising many by sliding inside from his right tackle position. Chris Williams and Shelley Smith will share the left guard duties. All in all, the offensive line is where this game will be won or lost for the Rams this Sunday.

49ers defense

The 49ers defense is coming into its own after some up and down performances early in the season. The team is loaded with established and rising stars, but there are still some lesser known elements to this defense. One area where the 49ers have developed some success is depth along the defensive line.

Defensive tackle Ray McDonald suffered an ankle injury in Week 10, and sat out the 49ers games against the Saints and Washington. In his place, the 49ers started former undrafted free agent Tony Jerod-Eddie (in his second year). He got a majority of snaps at defensive tackle, but he also rotated with fellow undrafted free agent Demarcus Dobbs (in his third year). Jerod-Eddie and Dobbs have not played at the level of McDonald, but they have been solid.

Whether or not McDonald plays, Jerod-Eddie and Dobbs will both get a solid amount of playing time. Given the strength of the Rams run game, even if it's Cunningham starting, they will be tested plenty.

Rams Defense

All eyes will be on the concussion protocol progress for Trumaine Johnson. I doubt he'll be ready to go Sunday, after being knocked out cold during the Chicago game. So into the picture steps rookie corner back Brandon McGee. This is where a kind of giddy laughter starts to peek out as I write this. You see, it just so happens the 49ers may have found their passing game Monday night. Great timing, right? Not only is Colin Kaepernick's favorite receiver - Mario Manningham - back and healthy, this guy named Michael Crabtree chose this moment to be declared fit for duty. Let's not forget Anquan Boldin and Vernon Davis either... The 49ers are going to literally rain passes in McGee's direction all day. The key to this game for the Rams is simple: Find a way to help McGee without sacrificing run coverage - which hasn't been all that great this year. Everything will hinge on McGee if he's the starter this Sunday.

Containing Kaepernick is a secondary concern, but still worth mentioning. His ability to run the ball can't be overlooked, nor can his strong arm for throwing quick, lazer-like passes. The soft coverage the Rams' secondary seems bent on playing, will leave receivers open for quick slants and bubble screens.