Right end Justin Smith is the big-name player on the defensive line. It all starts up front for a 3-4 defense, but it usually starts with the nose tackle.
In the case of San Francisco, Smith is key to a lot of the things they like to do on defense. He is an excellent two-way defender that is particularly strong against the run. He already has 21 tackles this season, which is an unusually high number for an end in this scheme.
Generally speaking, the ends in the 3-4 play two-gap defense, tying up blockers so that the linebackers can flow to the ball. In Smith's case, the gaps that he maintains switch from inside to outside depending on the situation, which is one of the reasons that the 49ers are allowing only 3.06 yards per carry on 49 attempts up the middle even though nose tackle Aubrayo Franklin is not a dominant defender.
Charlie Johnson will have his hands full on Sunday, but Smith only has one sack thus far this season and is less skilled rushing the passer than he is defending the run, so Johnson will probably not need help in the passing game.
Teams are averaging only 3.21 yards per carry on 24 carries to Smith's side of the field, but the Colts are averaging 4.82 yards per attempt around left end and left tackle, so they may want to take a few early shots at Smith and outside linebacker Parys Haralson in the early going and see if they are successful. They are not likely to be effective up the middle, even though they average 4.46 yards per carry in that area, just because San Francisco is so stout of the middle, given Smith's versatility and the abilities of their inside linebackers.
Indianapolis has not been overly effective running behind Ryan Diem and left end Issac Sopoaga has allowed only 2.37 yards per carry around right end, so it is unlikely that the Colts will challenge the matchups on that side of the field.
The interesting thing about the 49ers' flavor of the 3-4 is that it is very vanilla. They tend to line up seven players in the box in fairly standard formations and rarely rush more than four players.
n prior seasons, Peyton Manning struggled to diagnose where the fourth rusher was coming from in most 3-4 defenses, but he has solved that issue this season, and identifying that fourth man should be fairly easy for him on Sunday. San Francisco does have 13 sacks on the season and recorded two sacks against the Texans in Week 7, but Manning has only been sacked two times so far in 2009, so he will most likely have sufficient time to scan the field and find his target, even though he will probably be lean on available targets on Sunday.
Inside linebackers Patrick Willis and rookie Scott McKillop are high effort players that are also exceptional athletes. Willis is the star of this group, with 59 tackles, three sacks, four passes defended, two interceptions, and two forced fumbles in only six games.
The 49ers coaches use Willis in a variety of different ways, even if they don't vary his position on the field very much. He is the one blitzer that Mike Pollak and Ryan Lilja need to watch out for in the passing game and Manning will need to be cognizant of where he is at all times.
Willis will get his numbers, there is no stopping that. What the Colts need to do is make sure that they do not serve up a gamebreaking play to him, because he will take full advantage of any opportunities presented to him. Ball security and awareness of where he is on the field will be key.
Outside linebackers Haralson and Manny Lawson are solid run defenders and Haralson is most commonly utilized as another end against the run, while Lawson — who played defensive end in college — is primarily used as the aforementioned fourth pass rusher. Lawson has not found his groove at the position, though, and has only 1.5 sacks on the season, with one of those coming against Houston in Week 7.
Diem should be able to handle some combination of Sopoaga and Lawson, but Indianapolis will probably need to roll protect over to that side of the field in passing situations, most likely with Gijon Robinson, who should see plenty of playing time given the injuries to the receiving corps.
As of Thursday, Reggie Wayne and Anthony Gonzalez had not practiced with Wayne listed as questionable and Gonzalez listed as doubtful. If Wayne does not improve, it could mean a call-up from the practice squad for Taj Smith or John Matthews, and certainly more playing time for Hank Baskett.
Austin Collie got just a few reps on the perimeter during the preseason and in training camp and cannot fill Wayne's shoes. Pierre Garcon struggled in Week 7 against the Rams and needs to step up against San Francisco on Sunday.
Cornerback Nate Clements is the most talented player in the 49ers secondary and has allowed only 6.3 yards per attempt to the short area of his side of the field and a very impressive 5.73 yards per attempt to the deep right. The numbers and the game film prove out that he has those numbers because he tends to give his receiver a fairly large cushion.
If Wayne is unavailable, look for Manning to throw primarily screen passes and quick hitches to Garcon in order to take advantage of that cushion and Garcon's ability to get yards after the catch. The wrinkle here is that, although Clements is listed as the left cornerback, he tends to shadow the other team's most talented receiver.
On the other side of the formation, Shawntae Spencer has proven himself to be vulnerable in the deep passing game, giving up 10.7 yards per attempt on ten passes to that area of the field. The safeties are also vulnerable to play-action passing and deep passes over the middle since starters Michael Lewis and Reggie Smith have missed significant time due to injury.
Dashon Goldson and Mark Roman have yielded 15 yards per attempt on 14 pass attempts to the deep middle. If Manning can freeze the safeties with play-action — or look them off or fool them with pump action — there are tremendous opportunities available for a passing attack that has averaged 18.7 yards per attempt to the deep middle.
Injuries are the key factor here, as a healthy Indianapolis squad would this unit at all depth levels. If Wayne and Gonzalez are not able to play or are limited by their ailments, look for Manning and the Colts to still go after the safeties and the middle of the field in the deep and intermediate zones, even if it is just with Baskett, Collie, Garcon, Robinson, and Clark.
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