You’ve heard about the reunion taking place this Sunday, yes?

Chuck Pagano, fresh back from kicking leukemia’s ass (thankfully), will be returning to Baltimore when the Colts take on the Ravens. Pagano was on Baltimore’s coaching staff from 2008 to 2011, serving as a secondary coach and coordinating a dominating defense before being hired by the Colts in 2012 to fill their vacant head coach position. Now at Indianapolis, the Colts defense hasn’t been as good as Pagano’s with the Ravens because it’s transitioned to a 3-4 and has several new parts. They’ve struggled all season long, and they’ll have their work cut out for them on Sunday. They allow the third most rush yards per game (137.5) and second most average per rush (5.1), and they’re facing Ray Rice.

This is a big concern for the Colts defense going into the game. They’ve given up far too many big runs this season and the last time they faced a run package like the Ravens’ was last week, when they allowed 171 yards and 5.5 yards per rush to the Texans. Like the Texans, the Ravens are proficient in running zone stretch concepts, especially the outside zone, and the Colts really don’t defend it well, often losing sight of their gap responsibilities and lacking discipline in general. The Ravens are well aware of this, as tight end Dennis Pitta pointed out.

“You look at how they played against the Texans,” says Ravens tight end Dennis Pitta. “They can be susceptible to big plays [emphasis mine] but at the same time I think they do a great job of creating turnovers and putting you in bad situations. They’ve got a lot of speed on defense and that’s always difficult to handle.”

The Texans’ big plays against the Colts came on both inside and outside stretch concepts. The two complement each other, and the latter is sometimes called upon first. Against the Texans, the outside zone hurt the Colts because they were unable to get to the sideline and set the edge.

One particular play illustrated this quite well, as their three-man front was unable to match up with the Texans’ “12″ personnel and they ran the outside zone to their left.

The goal of this run concept is for the offensive linemen to reach across the face of the defenders they’re blocking and essentially build a wall of blocks between the defender and the sideline. If this is done, the running back has a significant alley to the outside, especially if the split receiver administers a block on the cornerback. This, precisely, is the issue that the Colts ran into when they traveled to Houston last week. Although they won, which is all that matters, they may not have the same result tomorrow if they are unable to slow down Ray Rice, backup Bernard Pierce, and the devastating lead blocks of fullback Vonta Leach.

When the Texans got the Colts moving downhill and really stretching themselves thin to set the edge on the outside, they were able to call on the complementary inside zone stretch concept.

This one is slightly different than the outside zone, as it features the offensive linemen drive blocking prior to executing their combination blocks. What it also does is change the keys of the ball-carrier from the outside hip of the tackle to the guard, meaning he’s more likely to find the cutback lane on the backside of the play.

Arian Foster did this well in the red zone when the Colts overloaded the strongside by covering up the center through the right tackle. This meant that on the backside, inside linebacker Pat Angerer (#51) was alone with defensive end Dwight Freeney against three Texans blockers: a numbers advantage for the offense. Once the overloaded side slid outside, Foster had a natural crease established in the middle of the field, which was a bad deal for the Colts, and it was further exacerbated when Angerer and Freeney were blocked and the supporting safety was out of position.

This is a significant concern going into the game, especially with the combination of Rice and Pierce. The two runners have different styles, as they complement each other with speed and (slightly more) power, but both can run stretch concepts effectively. The two ball-carriers combined for nearly 1,700 yards this season and they’re dangerous on these concepts. Rice, in particular, is exceptional while stretching the defense wide before finding and hitting a crease vertically, knifing through the teeth of the defense and then breaking ankles at the second level. In Week 14, the Redskins witnessed it on a 46-yard run.

Baltimore was lined up with Rice and Leach in the backfield and Pitta as a wing. Pitta was expected to kick out the outside linebacker of Jim Haslett’s 3-4 “Okie” (both guards uncovered) front. At the snap, quarterback Joe Flacco turned around and extended his right arm for the handoff to Rice, who looked to press to the outside. As he neared the heels of his blockers, he noticed that nearly the entire Redskins front-seven slid to the outside in hopes of forcing Rice to the inside. There was only one problem though: there was no one inside to stop Rice.

Both of the contain defenders were cut blocked to the ground. There was a gaping hole in the middle of the defense and no one to plug it, so Rice stuck his inside foot into the ground and turned upfield. Once Rice sliced upfield, the deep safety and supporting run defender was forced to come downhill. As you’ll see in the still-shot below, he took too narrow of an angle and himself out of the play, allowing Rice to make another cut to the outside and continue to run.

If Rice is able to get into the open field, the Colts are in serious trouble because he has the quickness and vision to turn up the field and make would-be tacklers miss. Another concern that arises from the Ravens’ running game, if it is indeed successful, is that Flacco will be testing the foot speed of the Colts cornerbacks by throwing vertically to wide receiver Torrey Smith.

As we all know, Flacco is hit or miss as a passer. But if the Colts don’t make the offense one dimensional and allow Flacco to throw off of play action, there’s a good chance they will exit the playoffs early.