Matchup breakdown: Rams-Titans

EARTH CITY, Mo. -- Three matchups to watch in Sunday's game between the St. Louis Rams and Tennessee Titans.

The Rams run defense vs. Tennessee running back Chris Johnson

Over the past two weeks, the Rams run defense has made huge strides, slowing down Carolina considerably and then completely shutting down Seattle and Marshawn Lynch last week.

The Titans don't present the same level of running game that the Seahawks or some of the team's other opponents do but they have the ability to break big ones in the run game behind Johnson.

Through seven games, Tennessee is 18th in the league in rushing, posting 102.9 yards per game. Johnson is averaging just 3.2 yards per carry and continues to struggle to meet the lofty standards he set while Rams coach Jeff Fisher was in Tennessee.

Still, Johnson possesses the type of game-changing speed that can significantly alter a game. Fisher and former Titans such as cornerback Cortland Finnegan and end William Hayes have provided plenty of caution that Johnson is still capable of hurting the Rams if they don't do all the right things when he touches the ball.

"His numbers are down but the skillset is not, it's still there," Fisher said. "He's still got the vision, he's still got the explosiveness and he can go the distance at any time. We talk about having to adjust our pursuit angles for him because it's a different speed than what we're used to playing."

Rams receiver Chris Givens vs. Tennessee cornerback Alterraun Verner

It's no guarantee that these two will square off all day this week but whichever Rams receiver has the misfortune of seeing Verner across the line is going to be in for a long day.

Verner has burst onto the scene in this, his fourth season. He has four interceptions and a pair of fumble recoveries and ranks first among all defensive players in the league in disrupted dropback percentage, coming up with a pass deflection, batted ball, sack or interception on nearly 5 percent of opposing dropbacks.

The Titans won't hesitate to use Verner and fellow corner Jason McCourty in press-man coverage. Verner is a physical, feisty type who will spend most of his day at the line of scrimmage when Tennessee isn't playing split safety zone.

While Verner presents a difficult challenge, playing a team that primarily plays man coverage does provide some opportunities for big plays. Givens is the most likely to hit one of those home runs and the Rams could certainly use one this week.

Rams defensive end Robert Quinn vs. Tennessee left tackle Michael Roos

Quinn absolutely dominated Seattle's Paul McQuistan last week to the tune of three first-half sacks. He did the same against Arizona's Levi Brown in the season opener with those two games creating six of his 10 sacks on the season.

There's no doubt that Quinn can take advantage of and dominate players who are clearly inferior. He's proved capable of doing the same against better tackles too but he'll get a much stiffer test this week in the form of Roos.

Roos was a Pro Bowler in 2008 and is known for a mean, nasty streak that makes him difficult to deal with for an entire game.

Quinn brings the type of speed and athleticism that can give a mauling type like Roos trouble. The Rams don't need Quinn to give them three sacks every week but they do need him to draw attention and help set the tone for a defense that must continue to lead the way for St. Louis.