What needs to be replaced?
A Base WLB who also is charged with man coverage against RB and TE. Someone who can provide run support to the weakside. Someone who can remain on the field in dime situations as the only LB.
In our base defense he has to provide coverage to the A gap depending on the call up front. In this "Under" configuration, he will have the 3-tech covering the guard against the run most of the time. Brandon Marshall should do fine in this role.
In our nickel defense he has to provide both zone and man coverage depending on the call. Last year sometimes the Broncos utilized the WLB as the coverage man against a TE. Other times they used a S. Sometimes the Broncos will blitz and the man coverage will be taken over by the safety. In nickel, Jack Del Rio was more apt to blitz, and much of that could be due to the loss of Von Miller for long stretches. Brandon Marshall can stay in the coverage role. What we should be asking is, what are we replacing in the nickel MIKE role?
In dime, there will be more than enough DB/S to cover the 5 expected receivers. That MLB ends up being the only defender on that second level. He has to stay here and zone for a possible checkdown or crosser that might be coming short. Not only that, he has to make sure the QB doesn't bust off a big gain on a scramble.
Fits as our base 4-3 Under WILL LB
The two names that pop out are backup Brandon Marshall and Steven Johnson. Last season Steven Johnson made the team as a backup WILL to Danny Travathan as the Broncos only kept 6 linebackers with Von Miller on suspension. This year, Brandon Marshall has earned his way as Danny's backup and has even remained in the lineup next to Danny in the nickel defense. There is still a long way to go but Brandon Marshall should fill in fine on the weak side as a base WILL.
Fits as our MLB in Nickel
If Brandon Marshall makes it onto the field as our base WILL, he should remain here in nickel. If the Broncos decide to do this they have several options as that coverage MLB.
How about an abundance of TJ Ward? Broncos have been doing this anyway, especially in game saving scenarios. I understand the meta game. It's one thing to have him here when the Broncos are leading and the opposing team has to pass. What about when they are tied and ahead? If the Broncos are that worried about the issue you have to consider their opponents in the first three weeks. More on that later. But you can combat this a number of ways. The first is to run your nickel big package with larger DT's. That means the possibility of replacing Sylvester Williams with Kevin Vickerson. One thing I think people have to remember is that both Von Miller and DeMarcus Ware disrupt the rushing and passing games.
The LB to get a first crack at the job is most likely rookie Lamin Barrow. This was the role the Broncos drafted him for in 2014. So far Marshall has held him off. The Broncos are a trial by fire team --they put a lot of stock into what happens on the field. This is a perfect opportunity to see what the rookie can bring after bringing him along slowly during practice.
Next and this is just pure speculation based upon what I have seen in practices. Lerentee McCray looks very natural in pass coverage. In the one on one matchups I've watched he's able to diagnose a checkdown out of the backfield quickly, and he's also able to hang with a TE over the middle.
The next option is Nate Irving. Whoa, threw you a curveball there right? In nickel, you're either going to have that WLB which in this case is Brandon Marshall or your safety covering a TE. A lot of the time you're going to have that MLB stay in to cover the checkdown in the flat or short middle. Nate Irving can do that fine. If they start running crossers with a TE you start using him to check the TE at the LOS before he gets into that route. The biggest danger here is perhaps when an offense sends the RB wide. Could present some issues especially with bunch coverages. Something the Broncos staff should be working with the LB's anyway.
What if the Broncos decide they want to keep Brandon Marshall as that Coverage MIKE in the middle like he's been doing? You're replacing a coverage guy with preferably another coverage guy.
Shadow that TE with TJ Ward leaving Marshall on the RB. TJ Ward has shown himself to be capable against TE's in the passing game. He is physical with them and can keep up with their speed. If the opposing team moves to 4 WR, move to dime.
Fits as our Dime LB
This guy has the easiest role besides maybe the passrushers and deep safety in this package. His one goal is to stay in the middle. The other guys in the defensive backfield have man coverage. Your three safeties will be Moore, Carter, and Ward, with Chris Harris Jr. on the slot and most likely Talib and Webster on the outside. Here you can keep two deep with bracket coverage on the outside, or provide man and bracket coverage while only one stays deep. Lots of possibilities on matchups here, but as far as that MLB, his goal is to stay in the middle. Brandon Marshall could surely do this job.
Sizing up our opponents
Against this team you are more likely to see a lot of 2 TE and 2 RB sets on base downs with a mix of 20, 02, and 11 personnel on passing downs. How the Broncos play is entirely based upon how they utilize Aqib Talib. Talib has shadowed receivers at points during games, but for the most part will stay at that left CB position. This is getting ahead of ourselves though because the Colts can certainly move their WR's around to gain matchups.
Do the Chiefs have three WR's they can field at the same time? Joking aside I expect there to be a lot of 2 TE and 2 RB sets most of the time. The issue Kansas City presents will be with their TE Travis Kelce, and RB Jamaal Charles out of the backfield. In our base I think Brandon Marshall will be fine on Kelce. Split wide, it brings up new issues. In nickel you can bring TJ Ward in to cover the TE with two-deep over the top.
They will flash 11 personnel more often with Percy Harvin. They also may flash 4 WR with both Harvin and Richardon, two bonafide speedsters that will stretch the field. The running game is combated fine by our 4-3 Under with Marshall as the WILL. When the move to 3-WR sets, Marshall can cover their TE's. In Dime, I want Marshall in the middle with a couple of DB's on their WR.
Each team presents different issues. Indianapolis presents the biggest issues when they play their 3-wide and 2-TE sets. Kansas City gives you the biggest problem against a RB in coverage with Jamal Charles. That may take more of a zone approach on the outside to keep plays in front of players. Seattle gives you the best flexibility on the outside with their 3-WR and 4 WR sets because of the speed on the outside. That puts stress on a different part of the coverage however.
Until Danny Trevathan comes back into the lineup, the Broncos have many in house options they can prepare before the season starts. With Del Rio leading, someone who has showed creativity with personnel in dire times, you're likely to see a mix of options going forward. The great thing about the Broncos personnel is the fact that they have so many talented players that can do multiple things. Your standouts at the moment to help replace Danny Trevathan are Brandon Marshall and TJ Ward. Some other guys you will have to keep an eye on are Lamin Barrow, Lerentee McCree, and Nate Irving.
The Broncos have many options and plenty of time.
One of the options not even discussed yet is our pass rush. After what you've seen so far, you think the QB is going to have a ton of time to get a man open?