AFC North: David Stewart
The Titans haven't exactly feasted on patsies to stay undefeated and at the top of the AFC South. But for a team that relies so heavily on the ground game, the Ravens' No. 2-ranked rushing defense has to be considered Tennessee's biggest potential hurdle to date.
Moving the ball against coordinator Rex Ryan's high-tempo and versatile defense won't be an easy task, especially for a Titans club that lacks a big-play receiver and has hitched its wagon to journeyman backup quarterback Kerry Collins. But it can be done, and Tennessee probably won't need an inordinate amount of points from the offense to walk away 5-0.
The Titans' two-headed rushing attack is so effective because powerful running back LenDale White and speedy rookie Chris Johnson are polar opposites who provide a fastball/changeup combo that is difficult to prepare for and adjust to. That, and the team has no shortage of able and willing blockers to create space for that duo to maintain and finish drives.
White is a punisher by nature, but he has lighter feet than most running backs his size and maneuvers well in tight quarters. Repeatedly tackling the 235-pounder quickly grows tiresome for defenders, and White can be especially physical on isolation runs burrowing behind underrated fullback Ahmard Hall, a bruiser in his own right.
Meanwhile, Johnson has elite speed and can threaten the edge like few runners in the NFL. He has excellent vision and impressive patience. (Tennessee has begun using a stretch play to better utilize his impressive skills.) He can change a game in one play if he clears the second level of defense, and the additional threat of his pass-catching ability may force Ryan to tone down his blitz (which can benefit Collins and the run game). Johnson can have success stretching the field, possibly from a detached position, against the Ravens' heavier 3-4 linebackers.
The unsung heroes are the blockers. Veteran center Kevin Mawae, the unit's leader, is smart, tough and gets everyone on the same page. Left tackle Michael Roos, an athletic finesse blocker, is one of the league's best at his position. Right tackle David Stewart, a mauler, is a nasty strong-side blocker who excels in the run game. Hall is no household name, but maybe he should be. A prototype downhill isolation blocker, he can blow a linebacker out of the hole in short-yardage situations or find a smaller safety on outside runs. The versatile tight ends are chess pieces who can be moved around to create better run-blocking angles. Even the wide receivers are accomplished blockers, a trait coach Jeff Fisher covets.
Tennessee's run game typically tilts to the right, behind Stewart, and that should hold true against Baltimore -- especially early. Stewart will have his hands full with oversized defensive end Trevor Pryce, but Hall and the tight ends provide extra muscle. The Titans can't quit on this strategy if it doesn't pan out initially. Hammering the right side will encourage aggressive right outside linebacker Terrell Suggs to cheat on his back-side contain responsibilities and flatten out down the line in pursuit. If the Titans notice this tendency, expect Johnson to get his chances to cut back against the grain into the area Suggs vacated. That's a recipe for long runs against a defense that doesn't give up many.
Scouts Inc. watches games, breaks down film and studies football from all angles for ESPN.com.