Film room: How DL Mike Purcell forced a veteran off the Broncos' roster

Several key position battles are gaining more clarity as the Denver Broncos continue to March through their five-game preseason gauntlet. Though there have been a lot of guys playing their way off of the roster over the past couple of games, there has been one guy that has made a table-pounding effort to land a spot on the Broncos' opening 53-man roster.

That man is 304-pound defensive tackle Mike Purcell.

In Saturday night's 10-6 loss to the Los Angeles Rams, Purcell was the best defensive player for the Broncos all night, continuing his ascending play throughout the preseason. His stellar effort landed him a 91.1 grade from Pro Football Focus, the single highest grade of any Broncos player this preseason.

Now, if one were to attempt to scout the box score, this claim would sound ridiculous. Purcell only finished the night with a single tackle. However, diving into the tape reveals a massively disruptive interior defender that was constantly in the Rams backfield in the running game.

Purcell was often seen getting an insane jump off the snap, blowing up plays in the backfield before they even had a chance to get started.

On the opening possession of the game, the Rams were threatening an early score after a 51-yard pass play from Brandon Allen to Mike Thomas. Fast forward a couple of plays, and Purcell makes his presence known on back-to-back snaps.

Play 1

Here on 3rd-&-1, Purcell shows nice stack-and-shed ability going one-on-one against the Rams' center. He anchors at the point of attack, then flings his opponent away with negligent ease, cleaning up what was an amazing amount of penetration from DeMarcus Walker in the backfield, stopping the play for no gain.

It's not the flashiest of plays to begin this film breakdown, but it was something that Purcell showed on a regular basis against the Rams and an area he has been improving throughout the preseason. This shows some massive upper body strength from the big defensive lineman, and if Purcell can continue making plays like this, he could carve out a niche as a rotational run defender for the Broncos defense.

Play 2 (the very next play)

After stuffing the run in the hole on third down, Purcell appeared to have been shot out of a cannon on the next snap. He crosses the face of the center and gets several yards into the backfield, drawing what should have been a holding penalty.

Despite not getting a yellow hankey, his penetration blows the play up immediately, allowing rookie LB Justin Hollins to drop Rams' RB Darrell Henderson for a two-yard loss, giving the Broncos offense the ball.

This is just one of several times that Purcell was the first Broncos defender out of his stance at the snap. For a man north of the 300-pound mark, the guy has an insane burst and first step. There were at least five plays of this caliber on Saturday night from Purcell, and a handful more where he was still wreaking havoc up front without getting this kind of penetration off the snap.

However, Purcell only seems to be a two-down player at this time. For whatever reason, the same quick-twitch propensity that he displays as a knifing penetrator disappears in passing situations.

There were times that I wasn't sure if he was maintaining his gap control at the line of scrimmage, or just completely stonewalled at the point of attack. Most of those times, he was facing a double team from the Rams offensive line.

Play 3

This is an example of just that. Notice how high Purcell's pad level is coming off of the snap, as well as the lack of hand fighting to try to break free. Again, Purcell may be playing with a heightened sense of gap discipline here, but the lack of hand play to try to free himself from the double team wouldn't have allowed him to make the play had the Rams QB utilized his escape route to Purcell's right side.

This may be me being a bit too critical, but I wanted to show you all one of the biggest flaws to Purcell's big night. Sure, he was spectacular against the run and had a couple of nice plays rushing the passer, but those nice plays were few and far between. In fairness, we're gonna take a look at his best pass rush rep of the night. This one is fun.

Play 4

When Purcell does keep his pad level low and get his hands out in front, this is what happens. He shows off a massive bull rush here, putting the Rams' center on skates and walking him right into Brandon Allen's lap. The pressure coming off the edge forces Allen to step right into Purcell, who sheds away and make a great hit to force an errant 'throw'.

With newer NFL rules designed to further protect the QB from taking wicked shots like this, Purcell also does a nice job of making a clean hit on this play. He wraps up and still makes forcible contact on Allen, but avoids driving him into the ground with his shoulder.

There aren't a lot of pass rush chops coming from big 98, but having a massive player of his stature that can collapse the pocket with plays like this is a major cog of successful defensive football.

Though it isn't Purcell's biggest strong suit, there are some flashes at times, especially if he is the first player off of the snap.

Let's get back to what he does best by showing you his most impressive play of the night.

Play 5

Right at the start of the fourth quarter, Purcell looked as if he was shot out of a cannon, slicing through the Rams' offensive line and almost taking a hand-off out of John Wolford's hands.

Rams RB John Kelly is a very tough runner, and it showed on this play. Even though Purcell didn't manage to secure the tackle, the play still went for negative yardage in the red zone.

This had no shot. Unfortunately, Purcell couldn't make the play himself or force the turnover, but it's because of his insane penetration off the snap that this play was dead on arrival.

Bottom line

Unfortunately, I didn't get to see the game live to comment on how Mike Purcell was playing on Saturday night. I did get to watch it on Sunday morning, and my takeaway was almost immediate.

If Mike Purcell's performance not only against the Rams but throughout the preseason to date isn't enough to land the former undrafted free agent out of Wyoming on the Broncos 53-man roster to start the regular season, I'm not sure what more it's going to take.

He has improved every single week, culminating with his efforts on Saturday, which despite going against second and third-string players for the majority of the game was still completely dominant from front to back, particularly in the running game.

The Broncos front office might agree as well. Early on Monday morning, the team released veteran DL Zach Kerr in what was a mildly surprising move, possibly opening up a spot for Purcell to step into. Either Purcell or DeShawn Williams, who has flashed a lot this preseason as well, could be the beneficiary of this cap casualty.

We'll know soon enough. The Broncos have to have their roster trimmed down by Saturday Aug. 31. Will Purcell be on it?

Follow Lance on Twitter @SandersonMHH.